THE PREMIER CASE AGAINST UNITARIANISM:

Why the Father Alone Being “God” Cannot Sustain the evidence and argument: Skip to Bottom for the formal argument or continue reading for the evidence and set up…

Today’s question allows for a pretty in depth argument. However, a major flaw and side issue in unitarianism and heretical sects is that they have to presuppose the bible is something it is not via a restorationist world view. This argument doesn’t get into the nature of the bible. But, if that’s your thing you can supplement the argument below with this too where we expose this restorationist flaw and explain: Why the Bible is Trinitarian – RobertDryer

Q. 48: Is God a Self or Personally Simple?

I. THE “CREATURELY IDENTITY” PROBLEM

In first-order logic or basic set theory, “=” can and often denotes strict, numerical identity. In a more technical sense, “=” denotes the identity relation (since it’s not purely a numerical notion), meaning that both sides name the very same object (typically in every respect). This means:

Reflexivity: x = x
Symmetry: If x = y, then y = x
Transitivity: If x = y and y = z, then x = z
Leibniz’s Law: If x = y, then any property of x is a property of y, and vice versa…

Such properties make sense for finite or composite objects, like people, numbers, or sets. For example, if “Alice = the person who wrote this letter,” then no second individual named Bob could also be “the person who wrote this letter” unless Bob literally is Alice in every respect. In a theological context, we distinguish “creaturely” identity claims from other forms of identification or participation (including phenomenological approaches to identity). For our purposes here we’re highlighting the more strict logical senses like number or equivalence relations. So, to be more specific, if someone says “the Father = God” in this same strict, exclusive sense, then “Father” and “God” refer to exactly the same object. If we also say “the Son = God,” transitivity forces “the Son = the Father,” which contradicts the clear biblical portrait that the Father and Son remain personally distinct.

Classical (orthodox) Christian theology (Nicene or SSGO) avoids this (“creaturely” strictness) problem by recognizing that God is infinite, noncomposite, uniquely incomparable, and capable of existing as three distinct “whos” (Father, Son, Spirit) in one “what” (the one divine essence). Thus, “Father = God” in a Trinitarian sense means “the Father fully possesses the single divine essence,” not that the Son or Spirit are excluded from it. Imposing a finite or “creaturely” identity scheme on the transcendent God inevitably flattens His infinite nature into a single finite entity, and orthodox tradition has always denied such flattening.

[Side Note] In Traditional Christianity, the understanding of God differs starkly from Unitarianism in three major ways:

God Is God’s Own Principle: Nothing precedes or causes God; He is uncaused, self-subsistent, and “simple,” meaning He has no parts or external composition.
Not Merely One Self: The same God is understood as three Persons in eternal relationship, not a solitary monad.
Creator vs. Creature: We must not treat God as if He were merely one item in the set of existing things. God transcends all categories.

Thus, when Christian theologians say God is His own ordering principle, they emphasize that only in God do essence and existence coincide without contingency. Yet God is also tri-personal, so He is not just a single “self” among many, but a living, personal, super-essential, super-abundant, perichoretic communion who is also the source of all that exists. [Side note over]

II. HOW UNITARIANISM NECESSARILY EXCLUDES THE SON AND SPIRIT

In “strict” or “biblical” Unitarianism, only the Father is truly God. That means if the Son were also “God” in the same sense, He would be identical to the Father, erasing their distinctness. Formally:

Let F = “the Father.”
Let G = “God.”
A strict unitarian says F = G, so all properties of G belong exclusively to F.
Because Scripture insists the Son is not the Father, the Son cannot also be G without forcing “the Son = the Father” via transitivity.

Hence, unitarianism either demotes the Son to a lesser, created being or merges Him with the Father (modalism). Classical Trinitarianism rejects both extremes by affirming that one infinite essence subsists fully in the Father, Son, and Spirit, distinguishing them by “begottenness” or “procession” (marking who They are, not what They are). I have done extensive work elsewhere showing how this distinction works in a relational context (see: https://robertdryer.com/defending-divine-simplicity/).

III. “WHAT WE’D EXPECT” LIST IF UNITARIANISM WERE TRUE

If unitarianism genuinely reflected the Scriptures and the earliest Christian faith, we would see all of the following:

Exclusive Reference to the Father as “God”

We would not find texts explicitly calling Jesus “God,” such as John 1:1 (“the Word was God”), John 20:28 (“My Lord and my God”), Hebrews 1:8 (“Your throne, O God”), or Titus 2:13.

No Worship of Jesus or the Spirit

We would not see prayers, doxologies, or worship directed to Christ or the Spirit in the same way as the Father.

No Triadic Passages

Sayings like “baptize in the name of the Father and of the Son and of the Holy Spirit” (Matthew 28:19) or “the grace of the Lord Jesus Christ and the love of God and the fellowship of the Holy Spirit” (2 Corinthians 13:14) would be inexplicable.

No Early Creedal Assertions

The Church would not need to defend the Son’s equality with the Father, as we see in the Nicene Creed (God from God, Light from Light, true God from true God).

The Holy Spirit Depicted Merely as an “It”

Unitarianism would treat the Spirit as an impersonal force, yet Acts 5:3-4 calls lying to the Spirit “lying to God,” showing He is a divine Person.

Scripture and early Church tradition run directly against these expectations. Indeed, the New Testament, archaeological findings of Jesus-worship (like the Eucharist) and the Megiddo Mosaic (which refers to Jesus as God in an ancient art inscription), and the creeds all indicate the opposite. Here are six more scriptural examples (beyond the ones mentioned) that show Jesus or the Spirit receiving divine worship or status:

Ephesians 1:21-22: Christ is exalted above all names and powers.
John 5:23: All should honor the Son just as they honor the Father.
Philippians 2:9-11: Every knee bows to Jesus, fulfilling Isaiah’s YHWH text.
Revelation 5:13-14: All creation worships the One on the throne and the Lamb together.
1 Corinthians 12:4-6: Spirit, Lord (Jesus), and God (Father) co-mentioned in divine work.
John 14:16-17: The Spirit is sent as “another Helper,” personally continuing Jesus’ divine presence.

As we see, unitarian expectations do not align with the biblical and historical record or with concrete examples. Scripture repeatedly calls Jesus “God,” gives Him worship, and treats the Spirit as fully divine.

IV. THE CONTINUATION OF THE SEPTUAGINT TRADITION, UNDERMINING UNITARIANISM

“Κύριος (Kyrios)” (Lord) for YHWH and Its Application to Jesus

The Hebrew Bible’s divine name YHWH was rendered “Κύριος (Kyrios)” in the Greek Septuagint (LXX). The New Testament continues this usage by boldly applying “Κύριος (Kyrios)” to Jesus, linking Him directly to Israel’s God:

Philippians 2:9-11: Every knee bows to Jesus, echoing Isaiah 45:23 (YHWH is the one to whom every knee bows).
Romans 10:9-13: Confessing “Jesus is Lord” saves, referencing Joel 2:32, which speaks of calling on YHWH’s name.
Acts 2:34-36: Peter cites Psalm 110:1 (“The LORD said to my Lord”) and proclaims Jesus as this enthroned Κύριος (Kyrios).

Meanwhile, “Θεός (Theos)” is most often used for “God” when referring to the Father. A naive reading might assume “the Father alone is God,” ignoring that “Κύριος (Kyrios)” was precisely how YHWH was rendered in the LXX (the main Greek Bible before the New Testament). By calling Jesus “Lord” in that same “YHWH sense,” the New Testament shows He shares the Father’s divine identity, yet is a distinct Person.***

If strict Unitarianism were true, we would not expect the New Testament to preserve or expand on the LXX tradition of “YHWH = Κύριος (Kyrios)” and then apply it to Jesus. Yet the New Testament does precisely that, indicating early Christians saw no contradiction in affirming the Father as “Θεός (Theos)” (God) and the Son as “Κύριος (Kyrios)” (YHWH incarnate). This breaks unitarian exclusivity, showing Jesus to be co-identified with the one God, not the same Person as the Father.

(keep this in mind as Unitarians will deny premise #3 below.)

V. A FORMAL CONTRADICTION?: A REFUTATION OF STRICT UNITARIANISM

We can summarize our first preliminary logical argument against Unitarianism like this:

Monotheism: There is one unique divine essence (Deuteronomy 6:4).
Unitarian Exclusive Claim: “Only the Father is God,” so if any other Person “is God,” that Person must be the Father.
New Testament Son-Deity: Numerous passages call Jesus “God” (John 1:1, John 20:28, Hebrews 1:8, Titus 2:13) or apply YHWH’s own title, “Lord,” to Him.
Distinct Persons: The Father and Son are separate Persons in Scripture.
Law of Transitivity: If X = Y and Z = Y, then X = Z.

Conclusion: From (2) and (3), if Father = God and Son = God in the same strict sense, then Father = Son. But from (4), the Father is not the Son. That is a contradiction. Therefore, unitarianism must deny either the Son’s real deity or the Father-Son distinction, both of which collide with the biblical record and early Christian testimony.

In short, unitarianism claims “Father = God” and denies “Son = God,” yet Scripture says both are God and distinct Persons. Logic reveals this as a contradiction. But let’s continue with the evidence as the argument can be strengthened once we understand the implications of the continued evidence.

VI. UNITARIANISM COLLAPSES, TRINITARIANISM REMAINS

The evidence for Christ’s full deity (and the Spirit’s divinity), alongside biblical monotheism and real distinctions among Father, Son, and Spirit, is irreconcilable with strict unitarianism. Unitarianism either relegates the Son to a lesser creature or merges Him with the Father-neither aligns with robust scriptural data or the earliest Church doctrine (John 16:13).

Trinitarian theology resolves these tensions by rejecting a finite approach to “the Father = God.” Instead, it affirms that an infinite, noncomposite God can be fully possessed by multiple Persons:

The Father is “God,” the unbegotten source.
The Son is “Lord” (YHWH incarnate), also called “God” in key texts, co-equal but begotten.
The Spirit is personal, fully divine, proceeding from the Father (and the Son in Western tradition), as seen in Acts 5:3-4.

Thus, the New Testament’s usage of “Κύριος (Kyrios)” from the LXX for Jesus and “Θεός (Theos)” for the Father, under one divine essence, fits a tri-personal concept of God, not an exclusively unitarian one. Strict Unitarianism fails to integrate this biblical evidence and basic logical principles while maintaining the Father, Son, and Spirit in proper tension. Trinitarianism remains the only consistent viewpoint that upholds the oneness of God, the full deity of the Son and Spirit, and their personal distinction, in line with both the LXX tradition and the New Testament.

VII. GOD AS A PERSONAL SIMPLE REALITY (RATHER THAN A “SELF”)

A. Having established in the earlier sections (I through VI) that (1) strict unitarianism collapses under the weight of biblical evidence, (2) the Son and Spirit cannot be demoted or merged without contradicting Scripture, and (3) God’s infinite essence can be fully possessed by multiple Persons, we now face a deeper question: How does this tri-personal, indivisible God avoid being just one “self” among many? In other words, if God is not a single unitarian subject, does that make Him multiple “selves” or an impersonal abstraction? The short answer, drawing on all prior insights, is that God remains personally simple—not a solitary “self,” but rather an eternal communion of Persons (Father, Son, Spirit) in one, unified divine essence.

We have seen in Section I that unitarianism fails if we take God as a finite, “creaturely” identity. We have noted in Section II that insisting “the Father alone is God” excludes or collapses the Son and Spirit. In Section III, we imagined what the Bible and early tradition would look like if only the Father were God—and found that Scripture and history show otherwise. Section IV emphasized how the New Testament continues the Septuagint (LXX) pattern of calling God “Κύριος (Kyrios),” then applies that same “YHWH” title to Jesus, making Christ co-identified with the one God. Section V’s formal contradiction demonstrated that unitarianism cannot maintain both “the Father alone is God” and “the Son is also God” yet distinct. Section VI concluded that only a Trinitarian view, acknowledging an infinite reality shared by the Father, Son, and Spirit, avoids these pitfalls.

However, one final clarifying point remains: we must not reduce God to a solitary “self,” as if He were one more personal agent among creatures. Instead, classical orthodoxy describes God as a personal simple reality: three distinct “Whos” in one simple “What.” The following explains why this matters and how it addresses potential unitarian objections about “multiple selves” or “a single self.”

B. Ambiguity of the Term “Self”

Unitarianism capitalizes on the confusion arising when we treat God as if He were simply one more subject in the universe—an individualized self. Yet the Christian tradition uses ὑπόστασις (hypostasis) or πρόσωπον (prosōpon) to describe the divine Persons, indicating that each Person is the undivided divine essence, without separating into discrete, finite centers of consciousness.

C. Emphasizing Simplicity and Personhood Together

Earlier sections (particularly IV and VI) clarified that the Father, Son, and Spirit share one infinite essence. This means there is no composition of “parts” or “selves.” Each Person is a subsistence of the same indivisible Godhead. The idea that “God is simple” is integral: God’s Personhood is not layered on as an extra piece but is intrinsic to His eternal being.

D. Relational Ontology

Sections III and V hinted at the significance of the Holy Spirit’s personal actions and the Son’s co-deity, showing that God’s inner life is already relational. This defies any suggestion that God must be a single subject who looks outward to creation for relationship. Instead, the one divine essence internally comprises eternal relations—Father begetting the Son, Son being begotten, and Spirit proceeding—without fragmenting God into separate “selves.”

E. Strengthening the Unitarian Critique

If God were a solitary “self,” He could not be both utterly self-sufficient and eternally loving apart from creation. A unitarian framework either denies God’s fullness of love until creation occurs or collapses all relational distinctions (leading to modalism). By contrast, Trinitarianism explains how God’s personal reality is entirely self-contained and eternally actualized among Father, Son, and Spirit, requiring no external referent for God to be love.

Earlier we underscored and here we put it all together that God is neither a single “self” (the unitarian error) nor a composite of three partly divine individuals. Instead, God is a personal simple reality: one infinite essence, three eternally relational Persons. This framework dissolves the major unitarian objections by showing that the unity of God is preserved by divine simplicity and the relational fullness of the Father, Son, and Spirit, while never lapsing into creaturely notions of multiple “selves.”

VIII. The Personally Simple God Argument against Unitarianism (or the Tri-Personal, Not a Solitary Self argument)

With all the preliminaries in place we now can have the full formal and strong argument against unitarianism vs. the proper view of God presented here.

PART VIII.1. THE OUTLINE OF THE ARGUMENT

Please Note: Part VIII.1, 3, and Part VIII.4 (“Personally Simple”), and Part VIII.6. below undergird and/or support Part I here below, since they explain how God can be one essence shared by multiple Persons. In other words, you can treat them-Part II, III, IV, and VI as the deeper theological and metaphysical basis for the initial premises below (particularly premises 5, 6, and 7) here. So please refer to them to get a sense of what the parenthetical references to those parts mean and are about.

1. Premise (Monotheism): Exactly one divine essence exists. This follows (A4) in the foundational assumptions, holding that there is “one God,” consistent with Deuteronomy 6:4 and the general Christian understanding of monotheism.

2. Premise (Distinct Divine Persons): Scripture and early tradition affirm that Father, Son, and Holy Spirit are each God, yet personally distinct. This aligns with (A1) in our assumptions, indicating that biblical data and early Church creeds witness to a tri-personal God.

3. Premise (Strict Unitarian Identity Yields Contradiction): If “Father = God” in a strict sense that excludes the Son, then the biblical depiction “Son is God but not the Father” becomes logically impossible. This follows (B2), noting that biblical texts call both Father and Son “God” while simultaneously distinguishing them.

4. Conclusion 1 (Unitarianism Fails): By reductio ad absurdum, unitarianism either self-contradicts logically or contradicts the biblical data (B3). If unitarianism denies the Son’s coequality with the Father, it conflicts with core scriptural affirmations of the Son’s and Spirit’s full divinity.

5. Premise (Infinite Essence): God is transcendent, noncomposite, and beyond finite identity constraints (C4, D1). This means applying “creaturely identity” rules (like strict numerical singularity) to God is inadequate.

6. Premise (Trinitarian Solution): God’s infinite essence is fully shared among three “whos,” none of which exclude the others from being God (C2). The Father, Son, and Spirit each possesses the entire divine essence without partition, explaining how God can be one “what” and three “whos.”

7. Premise (No Composition): Because God is simple, the Persons do not comprise different “parts” of God (D2). They are distinct only by relational origin—Father as unbegotten, Son as begotten, Spirit as proceeding—and do not divide the essence.

8. Conclusion 2 (Personal Simplicity): God is not a solitary self but a tri-personal, infinite essence. In other words, He is “personally simple” (D4), meaning that while God remains one in essence, He eternally exists in three personal modes without losing unity or simplicity.f

PART VIII.2. TRINITARIAN ALTERNATIVE: MULTIPLE “WHOS,” ONE “WHAT”

In classical (Nicene) theology, God is one in essence (the “what”) but exists as three irreducible Persons or “whos”—Father, Son, and Spirit. This addresses the biblical portrayal of each Person as fully God yet personally distinct:

(C1) Tri-Personal Monotheism:
Classical theology holds that God is “one in essence,” reflecting the foundational monotheism of Scripture (e.g., Deuteronomy 6:4). However, Scripture and tradition also affirm a threefold personal distinction—Father, Son, and Holy Spirit—coequal and coeternal.

(C2) Avoiding Contradiction:
Trinitarians avoid claiming “Father = God” in an exclusive sense that excludes the Son or Spirit. Instead, each Person wholly is God’s undivided essence, avoiding transitivity problems like “Father = Son.” Distinctions do not stem from separate parts but from each Person’s unique relational origin.

(C3) Biblical Corroboration:
Texts like John 1:1 (“the Word was God”), Matthew 28:19 (“baptizing in the name of the Father, Son, and Spirit”), and 2 Corinthians 13:14 (mentioning Father, Son, Spirit together) affirm the co-divinity and personal distinction. Early church councils (Nicaea, Constantinople) codified these insights, showing that tri-personal monotheism was the Church’s consistent understanding.

(C4) Infinite, Noncomposite Being:
God’s essence is infinite (“simple”), transcending finite identity constraints. The Father, Son, and Spirit each fully “is God,” yet they are not each other because they differ in relational origin (unbegotten, begotten, proceeding). Modern identity rules for finite objects (like Leibniz’s Law) cannot simply override the unique transcendence of God’s being.

Conceptual Note: “Three Whos in One What” does not rely solely on a relational ontology (e.g., SSGO). It has longstanding roots in classical substance metaphysics (Augustine, Aquinas), where “relations of origin” are eternal and do not fragment the one essence. SSGO merely reframes these classical insights into a contemporary mode of philosophical language.

PART VIII.3. “PERSONALLY SIMPLE,” NOT A SOLITARY “SELF”

Key Question: If God is not a single, solitary “self,” how do we avoid suggesting multiple deities?

(D1) Simplicity Premise:
God is simple—no parts, no composition, no external cause. Classical theology expresses this as “God’s essence = God’s existence,” or that God is “pure act.” Either way, there is no composite structure in God’s being.

(D2) Trinitarian Hypostases:
Scripture and the Nicene Creed identify three “whos” in a single “what.” Each “hypostasis” (or “persona”) does not divide the essence but wholly shares it, distinguished only by relational identity. The Father is unbegotten, the Son is begotten, and the Spirit proceeds.

(D3) Contradiction-Avoidance:
Thinking of God as a single self either denies the Son and Spirit’s coequality (clashing with Nicene teaching) or splits the divine essence (contradicting simplicity). By grounding difference in relational origin, we avoid dividing God while maintaining genuine personal distinctions.

(D4) “Personal Simplicity”:
God is not a lone “self” but a “personal simple reality,” an indivisible essence subsisting in three personal modes. These modes do not add “parts” to God’s oneness; they express one infinite act of being in distinct personal stances.

Conceptual Note: Instead of insisting “essence = existence,” one might simply say that God’s being is indivisible. In Self-Standing Givenness Ontology (SSGO), for example, the primary premise is that each divine Person is a self-standing relational mode fully expressing that one indivisible essence, thus preserving God’s absolute oneness alongside real personal distinctions. Whether we speak in classical Thomistic terms or modern relational categories, the core insight remains that no composite structure can exist in God, allowing for tri-personality without undermining divine simplicity.

PART VIII.4. UNITARIANISM AND ITS LOGICAL COLLAPSE

(B1) Strict Unitarian Claim:
Pure unitarianism argues: if “God” is the unique divine essence, then “only the Father = God,” meaning no other Person can also be fully God.

(B2) Scriptural Contradiction:
Yet, the biblical data depicts the Son and Spirit as fully divine (John 1:1; John 20:28; Acts 5:3–4; Hebrews1; Titus 2:13 and so on) while remaining distinct from the Father (John 14:16; Matthew 28:19).

If the Father exclusively is “God,” calling the Son “God” contradicts the biblical idea that “the Son is not the Father.”
The New Testament affirms both “Son is God” and “Son is not the Father.”
Hence, unitarian identity logic collapses into contradiction, requiring denial of either scriptural claims or logical implications of it.

(B3) Conclusion Against Unitarianism:

Unitarianism either morphs into modalism (merging Father and Son) or subordinationism (demoting the Son’s deity). Both conflict with the biblical-historical record. Under the principle of noncontradiction (A2), unitarianism proves logically and theologically untenable.

PART VIII.5. POTENTIAL OBJECTIONS

Objection 1: “The argument relies on biblical data or Nicene definitions.”

Reply: Indeed, this is an internal Christian argument. Its force comes from showing that, granted Scripture, creeds, and historically sensitive sense of identity logic, that unitarianism becomes self-contradictory, while tri-personal simplicity harmonizes all three.

Objection 2: “Talk of infinite, noncomposite being is not strictly first-order logic.”

Reply: I recognize that theological claims often surpass first-order logic but that doesn’t men it contradicts it. The arguments here demonstrates the synergy of biblical revelation with rational inference, rather than a logical impossibility.

Objection 3: “Could the Spirit or Son be lesser than the Father?”

Reply: That would clash with the statement “each Person is God” (Premise 2). No Person can be “partly” God; each fully shares the one divine essence. The consistent Trinitarian stance is the coequality of the divine Persons.

Objection 4: “We deny God is noncomposite or infinite.”

Reply: This strays from the classical Christian tradition, which holds that God is simple (A4, D1). If God lacks simplicity or infinity, then we enter an altogether different worldview where arguments about tri-personal unity or unitarian identity no longer apply in the same way. We’ll get deeper into this with objections 8 and 9.

Objection 5: “Isn’t this a ‘relational-only’ ontology, like SSGO?”

Reply: No. “Three Whos, One What” is inherently classical. Augustine and Aquinas already maintained that the Persons differ by relations of origin (Father as unbegotten, Son as begotten, Spirit as proceeding). SSGO simply re-presents this principle in modern, relational terms. Whichever metaphysical language we prefer—classical “substance” or newer “relational modes”—the Trinitarian conclusion holds.

Objection 6: “Must we accept ‘essence = existence’ for no composition in God?”

Reply: Not necessarily. Thomism uses “God’s essence = God’s existence,” but others can say if they want that God’s being is indivisible, needing no unifying principle. Furthermore, contemporary approaches like SSGO can portray each Person as an indivisible act of being. All the argument requires is God’s noncompositeness.

Objection 7: “What if someone rejects the Nicene reading and claims a unitarian biblical worldview?”

It is not unusual to encounter Christians who say that the Bible itself plainly teaches a unitarian God—one solitary divine person—and that later developments, such as the Nicene Creed, represent a departure from “purely biblical” faith. At first glance, this might appear compelling: why not simply take a direct reading of Scripture and conclude that only the Father is God? Yet, this line of thought overlooks how the Church has historically interpreted the Bible from the very beginning, guided by major councils and the promise of the Holy Spirit (John 16:13). In other words, the argument here deliberately presupposes what I call a Nicene worldview, one in which centuries of prayerful study and reflection—are to be understood to be Spirit-led and grounded in his promises—shaped how believers have understood God (1 John 4:6, 5:6).

A unitarian perspective, by contrast, often rejects large pieces of this Nicene consensus. Such readers might see no need for conciliar definitions or might downplay divine simplicity, insisting that the Father alone exhaustively represents God. The problem is that these moves result in a very different system of assumptions, one that relies heavily on post-Enlightenment identity logic (e.g., Leibniz’s Law) and a foreign philosophy that imposes itself onto biblical passages. This modern framework, which emphasizes strict numerical identity and treats relational distinctions as impossible in a single being, was not how the early Christians approached the biblical text. Thus, making much of unitarianism anachronistic. (See next objection #9 for more.) In fact, the earliest believers, as shown by the likes of Ignatius of Antioch and others, already saw the Son and Spirit as fully divine in real distinction from the Father, albeit within one God.

Because unitarianism sets aside the Church’s earliest Spirit-led discernment and the deep tradition of ecumenical councils, it has never developed a robust way to explain how Father, Son, and Spirit can each be truly divine while remaining one God. Instead, it tends to deny or reduce the Son’s and Spirit’s deity, thereby contradicting New Testament passages that explicitly call the Son “God” (e.g., John 1:1; 20:28) or show the Spirit exercising divine authority (Acts 5:3–4). As a result, a unitarian worldview is not just a different reading of Scripture; it is a break from the integrated method that has historically guided believers in harmonizing all scriptural evidence under the watchful lead of the Holy Spirit.

Objection 8: “Isn’t the Nicene Tradition a later invention, not rooted in the New Testament?”

Many people wonder whether the Nicene tradition—formally articulated in the fourth century with phrases like “one essence, three Persons”—arose out of thin air. Critics might view it as an invention that developed centuries after the apostolic era, completely separate from the New Testament itself. However, the Church has always maintained that Nicene theology is not an innovation but rather the natural outgrowth of apostolic teaching, clarified and formalized over time.

One need only look to the writings of early Christian figures such as Ignatius of Antioch, who lived in the late first or early second century, to see the seeds of Trinitarian thought already taking shape. Ignatius was closely connected to the apostles—tradition often associates him with the ministries of Peter or John—and his letters reveal a strong belief in the divinity of Jesus and a clear relational dynamic among the Father, Son, and Holy Spirit. Although he does not use the phrase “one essence, three Persons,” he calls Jesus “God” and speaks in ways that anticipate later Nicene formulations.

Other early patristic writers like Justin Martyr and Irenaeus also bear witness to a Church that acknowledged the Son and the Spirit as fully divine, even before the Council of Nicaea in 325. The New Testament itself provides the central groundwork—John’s Gospel, for instance, portrays Christ as the eternal Word made flesh (John 1:1, 14), and Paul’s letters highlight the Spirit’s divine agency alongside the Father and the Son (2 Corinthians 13:14). By examining these sources, we see a continuity that runs from the earliest Christian communities right up to the Nicene Council.

When the Nicene Creed finally declared Jesus to be “God from God, Light from Light, true God from true God,” it did so as a formal affirmation of what the Church had already believed in a less formally defined manner. In short, the Council did not introduce a foreign concept but rather gave precise language to a reality the Church had been practicing and defending from the beginning. This tradition is unbroken. Nicaea simply brought clarity and unity to a faith that was rooted in the New Testament and carried forward by the likes of Ignatius, Justin, and Irenaeus. Thus, while the phrase “one essence, three Persons” appeared in the fourth century, its substance was recognized from the earliest days of the Church, forming a continuous trajectory back to the apostles themselves.

Notice the trinitarian discussion is a tradition unbroken from the Bile through the ecumenical councils. Unitarianism doesn’t have a freestanding unbroken tradition working out its model of God authoritatively like the tradition that continued from the Bible well into the Roman empire and right on through today.

Objection 9: “Doesn’t unitarianism better preserve God’s oneness by treating Him as a single self?”

A unitarian might argue that the easiest way to preserve God’s oneness is by viewing Him as a single, solitary self—a numerical individual without any intrinsic distinction. At first glance, this seems simpler: oneself, one center of consciousness, one will. However, despite unitarian disclaimers, this “singularity ontology” in practice ends up imposing finite categories of identity on what classical theology calls an infinite, noncomposite God, failing to address crucial biblical and theological data.

First, unitarianism typically assumes the same kind of unity we observe among created beings: numerical singularity. Though some unitarian thinkers may dispute this characterization, their approach effectively treats God’s oneness in finite terms—“one equals one self.” But this breaks down when applied to an infinite, noncomposite essence. In classical Christian theism, God’s unity is not the isolated oneness of a solitary self but the indivisibility of His essence, fully shared by the Father, Son, and Spirit. A unitarian must explain away scriptural assertions of the Son’s and Spirit’s co-equal deity (e.g., John 1:1, John 20:28, Acts 5:3–4), usually subordinating them. This either contradicts the biblical witness or redefines it so heavily that it loses continuity with historic Christian tradition.

Second, the single-self model struggles with “God is love” (1 John 4:8). If God were a solitary individual, love would be something extrinsic—manifested only once He creates another to love. By contrast, a tri-personal God possesses an eternal, internal self-giving of love among the Persons, independent of creation. This yields a more robust explanation of how love is genuinely intrinsic to God’s very being.

This problem is huge once you understand it. Unitarianism typically embraces what we might call a singularity ontology, wherein God is conceived as a single center of consciousness or a lone “self.” This view relies on modern notions of strict identity (e.g., Leibniz’s Law) that treat God’s oneness essentially the same way we treat finite individuals—leading to a God who is numerically one in exactly the same sense a single human person is one. In this framework, there is no robust idea of a shared, indivisible essence that can be fully possessed by multiple “whos.” Instead, the default assumption is: one self equals one being.

By contrast, a constituent ontology (as employed in classical Trinitarianism) treats God’s oneness as grounded in a single, indivisible essence rather than in one center of consciousness. God’s unity resides in the fact that the entire divine act of being is fully present in each Person, rather than subdivided or allocated among them. This means unity is an ontological unity, not merely a numerical one. Father, Son, and Spirit each fully instantiate this one essence, so “being one” does not require being a solitary self. This constituaent ontology God the unique and incomparable ontological status; and, this in turn allows God to be declared, as the bible does, a the unique one whom surpasses and sustains all finite realities as their eternal source and ground of being. While creatures remain utterly dependent on Him and infinitely lesser by nature, they are freely and lovingly invited to participate in the tri-personal life of the Holy Trinity—an infinitely self-giving communion of love. Yet, this participation never diminishes the Creator-creature distinction, for creatures are drawn into divine life not by becoming God Himself, but by grace, in a way that perfects their nature without altering His transcendence or simplicity.

But, unitarianism’s singularity ontology effectively reduces God’s unity to solitary selfhood, employing modern, post-Enlightenment categories of personal identity that do not readily apply to an infinite, noncomposite being. Whatever the case is, there is a creature standard to unitarianism as there is 1:1 similarity to God and creatures in identity and self-hood the way they typically use terms about God. This is why we say unitarianism ultimately forces a finite, creaturely framework onto God, whereas a constituent ontology—rooted in the Church’s early theological reflection—better accounts for the biblical presentation of the Father, Son, and Spirit as co-equal possessors of a single divine reality.

Lastly, from a classical metaphysical standpoint, unitarianism’s version of simplicity often relies on negating any real distinction in God’s eternal life, allowing only modal or external differences. But Trinitarian “personal simplicity” understands the one essence as noncomposite while acknowledging that Father, Son, and Spirit are relational modes of that essence, each fully and distinctly God. This approach preserves a more profound unity, insisting that a single act of infinite being can be “lived” in three distinct, co-equal Persons without dividing or diluting that unity.

Hence, while unitarianism’s single-self model initially appears straightforward, the Trinitarian essence-construct ultimately offers a deeper, more coherent view of God’s unity—where love, personal distinction, and an indivisible essence abide harmoniously in the one God who is one uniquely in virtue of who and what it means to be this incomparable and beautiful reality.

PART VIII.6. FOUNDATIONAL ASSUMPTIONS

(A1) Scriptural and Historical Authority:
We rely on the mainstream Christian canon (Old and New Testament) and the testimony of early Christian creeds (e.g., Nicaea, Constantinople). This shapes our theological data, though we acknowledge it is not a purely logical requirement.
(A2) Principle of Noncontradiction:
Any valid doctrine must avoid internal inconsistency. Contradictory claims (e.g., “the Son is God but not the Father, yet only the Father is God”) cannot both stand.
(A3) Logical Identity:
Standard first-order logic treats identity as transitive, reflexive, and governed by Leibniz’s Law. However, we caution that these “creaturely identity” constraints do not straightforwardly apply to an infinite, noncomposite God.
(A4) Monotheistic Principle:
There is exactly one divine essence—“one God”—consistent with Deuteronomy 6:4 and general Christian monotheism.

God is not merely “a single self” but a tri-personal, simple reality. The Father, Son, and Holy Spirit each fully shares the one divine essence—without partition or confusion—fulfilling both biblical testimonies (the Son and Spirit are fully God, yet distinct from the Father) and the Church’s tradition guided by the Holy Spirit (John 16:13). Strict unitarianism, by contrast, fails under logical contradiction (finite identity rules forced on infinite God) and contradicts the early Church’s unbroken witness that the Son and Spirit are co-equal with the Father.

In place of a “self-based” model that reduces God’s unity to numerical singularity, Trinitarian “personal simplicity” offers a more coherent approach: one divine essence (the “what”) fully expressed in three irreducible, relational “whos.” Whether one articulates this through classical substance metaphysics (Augustine, Aquinas) or a modern relational ontology (SSGO), the core dogmatic insight stands. Moreover, this Nicene framework remains flexible enough to integrate emerging philosophical tools while staying firmly grounded in its biblical and historical roots—thus preserving God’s eternal unity, simplicity, and tri-personality in a manner consistent with both reason and revelation.

Conclusion

In the end, strict Unitarianism cannot account for the wide range of biblical and historical data. The Old Testament’s monotheism is deepened in the New Testament by revealing one God in Father, Son, and Spirit-a tri-personal reality that honors both the oneness of essence and the plurality of distinct Persons. By applying YHWH’s own title “Lord” (Kyrios) to Jesus, the New Testament shows that divinity is not restricted solely to the Father. Meanwhile, standard identity logic tells us that if the Father alone is “God,” then Christ cannot also be called God without collapsing His Person into the Father-yet Scripture consistently treats the Father and Son as truly distinct. Only a Trinitarian framework, which treats God as an infinite essence fully possessed by the Father, Son, and Spirit, can coherently integrate every strand of evidence: the Father’s primacy, the Son’s full deity, the Spirit’s personhood, and the unity of the one God of Israel. In this way, Trinitarian theology preserves biblical monotheism, honors the Son and Spirit’s deity, and remains faithful to both reason and revelation, in a way that strict Unitarianism does not.

Unitarians will never agree, but hopefully honest people can see its weaknesses and understand better how we get unity in Trinity and Trinity and unity from an orthodox and classical perspective. Ultimately, the Father, Son, and Holy Spirit, in their eternal self-giving and receiving, perfectly embody the Oneness of God. Their mutual exchange is the unique divine love that God is, for in God, to give is to fully receive, and to receive is to fully give.

*** Note

According to a deeply informed Catholic tradition (drawing on sources like the Catechism, the Councils, and Thomistic theology), a divine Person can be succinctly defined as a “distinct subsistence of the one divine essence”-that is, someone (Father, Son, or Spirit) who fully possesses the one, indivisible Godhead but is personally distinct through a relationship of origin (unbegotten, begotten, or proceeding). This definition emphasizes that there is only one divine essence or nature, yet three real “Who’s,” each wholly and irreducibly God.

In SSGO (Self-Standing Givenness Ontology) terms, the equivalent concept would be “a self-standing relational mode of the single divine essence.” Each Person (Father, Son, Spirit) is the entire infinite reality of God, viewed under a unique relational vantage (unbegotten, begotten, proceeding), without partitioning or dividing God’s unity. The Person is “who” God is from that distinct vantage, while the “what” is the one undivided essence (within a relational context).

P.S. I ran out of space. But if there was more time and room I would have mentioned more about these notables explicitly: the emphasis on how the Holy Spirit’s personal agency (e.g., interceding, teaching, guiding) conflicts with the unitarian tendency to treat the Spirit as an impersonal force or “presence,” as well as an explicit mention of Jesus’ repeated “I AM” statements (John’s Gospel) linking Him directly to YHWH (Exodus 3:14 and Isaiah’s use of I AM statement in the Septuigent). But on the whole, the argument above covers the key difficulties for Unitarianism and gives a good contrast to Trinitarianism. God is Personally Simple not a self. Fin.

The unitarian is not going accept the argument above which is why I started with a link to explaining why the bible is trinitarian without begging the question, a problem that’s going to be insurmountable for them to overcome. That’s because modern heretical sects, like unitarians are restorationists, and as such have to argue that a non‐trinitarian reading of the Bible represents the “original” or “restored” faith, and so then they must first assume that the canon—formed and preserved by communities that worshiped a triadic God—was corrupted or misinterpreted later. In other words, they must presuppose that the traditional trinitarian interpretation (and the very processes that led to it, such as canon formation and liturgical practice) is in error. This assumption—that the apostolic, proto‐Nicene reading was non‐trinitarian—is precisely what they need to prove their case. Unfortunately for them, because the canonical texts and early Christian practice already show a triadic framework (as seen in passages like 1 Corinthians 8:6 and the baptismal formula in Matthew 28:19), arguing for a restoration of a non‐trinitarian position using those texts forces one to reinterpret or even revise the historical context in which they were produced. This ends up being circular—one is using a Bible canonized by a trinitarian community to claim that the canon originally conveyed a non‐trinitarian (or “restored”) message, thereby assuming what one is trying to demonstrate. So, if a unitarian is also a restorationist, and is arguing for a non‐trinitarian view based on the same biblical texts, they are probably begging the question by already assuming that the original, apostolic interpretation was non‐trinitarian rather than trinitarian. For more see here: Why the Bible is Trinitarian – RobertDryer

Taken together, these links above and below (along with this page) provide both biblical exegesis and a metaphysical framework to answer most criticisms—namely, that the argument does not engage with the nature of the Bible or with the proper understanding of divine simplicity. They deepen the discussion by showing that the triadic nature of God is not an imposition of later philosophical language but is rooted in both Scripture and the lived experience of early Christians. Enjoy.

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