How the Old and New Testaments Reveal a Triune God

Question #32: How do the Old and New Testaments’ ‘I AM’ statements jointly reveal a single, tri-personal God?

One LORD, Three Persons: The Trinitarian “I AM” from Exodus to the New Testament

The survey below addresses two crucial points about the divine “I AM” language, clarifying that, in Trinitarian theology, “Persons” does not signify three independent selves in the modern sense but rather three distinct subsistences or hypostases within one superessential, co-inhering, perichoretic unity. Although these Persons bear names, their reality is ever greater: ἐγὼ εἰμί. How does this demonstration answer the question? Because the answer is a logic to the Bible. If someone is looking for an explicit treatise on simplicity below, it is not there by name, but its logic–one essence, no partition, yet three relationally distinct subsistences–points squarely to it. Enjoy!

The first crucial point is drawn from Exodus 3:14, traditionally understood as God the Father’s self-revelation (“I AM WHO I AM”), indicating His absolute being and independence. The second point follows from Isaiah’s “I am” passages, which, in the context of eschatological salvation, serve as divine self-declarations. In Christian interpretation, these passages foreshadow the Son’s claim of identity with Israel’s God, ultimately made explicit in the New Testament when verses such as John 8:28 and John 8:58 echo Isaiah’s “I am,” showing that the Son, too, shares YHWH’s eternal being. By weaving these strands together, we see how the Old and New Testaments converge on a Trinitarian vision of the one God–Father, Son, and Holy Spirit–without contradicting Israel’s monotheistic Shema (Deuteronomy 6:4).

In the Hebrew text of Deuteronomy 6:4, we read “Shema Yisra’el: Adonai Eloheinu, Adonai echad,” rendered in the Septuagint (LXX) as “Hear, O Israel: The Lord our God, the Lord is one.” This foundational confession establishes YHWH as the only true God with no rivals (cf. Deuteronomy 4:35, Isaiah 45:5–6). Yet nowhere does the Old Testament teach that God is a solitary monad devoid of internal distinctions; it simply denies the existence of other gods. Further revelation in Christ and the Holy Spirit deepens this oneness, showing the one LORD as Father, Son, and Holy Spirit.

Paul reconfigures the Shema in 1 Corinthians 8:4–6 by declaring that for believers there is “one God (the Father)” and “one Lord (Jesus Christ).” Here Paul deliberately mirrors the Shema’s language of divine oneness but distributes it between the Father and the Son. He uses the Greek term Kyrios (“Lord”), which in the Septuagint translates YHWH, to indicate that Jesus is no mere creature but truly YHWH Himself. By doing so, Paul demonstrates that the Father and Son share the unique identity of the one God, a truth that other New Testament passages expand by adding the Holy Spirit (as in 2 Corinthians 13:14), thus completing the tri-personal understanding of God.

This tri-personal reality is also hinted at in the Old Testament. Genesis 1:26 speaks of “Let us make man in our image,” which early Christian interpreters often saw as a glimpse of the Son’s co-creative role (John 1:3, Colossians 1:16). Similarly, the Angel of the LORD in passages such as Exodus 3:2–6 and Judges 6:11–22 is both sent by God and addressed as God, suggesting an internal distinction within YHWH’s identity. Texts like Psalm 33:6 (“By the word of the LORD the heavens were made”) and Proverbs 8:22–31 (which depicts Wisdom as “begotten” before all ages) anticipate John 1, where the Word made flesh reveals the Son’s eternal generation that was only made explicit through Christ’s advent.

Within the New Testament, passages such as John 1:1–18 affirm that the Son (the Word) is eternal and divine, with John 1:3 attributing the act of creation to Him, something only God can do (cf. Genesis 1). John 1:14 insists that the Word became flesh without ceasing to be God, placing the Son fully within Israel’s Creator identity while distinguishing Him from the Father. Likewise, Thomas’s confession in John 20:28 (“My Lord and my God”) would be unthinkable in a Jewish context if Jesus were not truly YHWH, yet He accepts this worship. The Apostle Paul underscores this same reality in passages like Philippians 2:6–11, where Christ is in the form of God and worthy of universal worship (Isaiah 45:23), and in Colossians 1:15–20, where the Son holds all things together and possesses the fullness of deity (Colossians 2:9). Titus 2:13 and 2 Peter 1:1 call Jesus “our great God and Savior,” while Hebrews 1 stresses that the Son is both worshiped by angels (Hebrews 1:6) and addressed by the Father as “O God” (Hebrews 1:8), declaring the Son to be the eternal Creator (Hebrews 1:10–12, citing Psalm 102).

The Holy Spirit is also revealed as truly God. Acts 5:3–4 equates lying to the Holy Spirit with lying to God. First Corinthians 3:16–17 portrays believers as God’s temple because the Spirit dwells within them, mirroring the Old Testament vision of YHWH’s presence sanctifying the Temple. In 2 Corinthians 3:17, Paul identifies the Spirit as the Lord, and in John 16:13–14 Jesus Himself declares that the Spirit will speak, guide, and glorify Christ, revealing personal attributes rather than a mere force. Thus, we discover one God in three Persons, as captured by the “I AM” proclamations. Exodus 3:14 (LXX) presents God the Father as “I AM THE ONE WHO IS,” emphasizing His absolute being. Isaiah 43:10–11 (LXX) insists, “I am God, and there is no one else who saves,” pointing toward eschatological salvation realized in the Son, a truth embraced in John 8:28 and John 8:58, where Jesus claims the same timeless divine identity.

These theological insights coalesce in the command of Matthew 28:19 to baptize “in the name (singular) of the Father and of the Son and of the Holy Spirit,” underscoring one shared divine identity. For a fuller picture of the Holy Spirit’s participation in the Godhead, numerous passages illustrate His possession of omnipresence, omniscience, and eternality (Psalm 139:7, 1 Corinthians 2:10–11, Hebrews 9:14), His sharing of divine work and unity with Father and Son (Matthew 28:19, 1 Corinthians 12:4–6, John 14:16–17), and His giving of divine life, truth, and grace (John 16:13–14, John 3:5–6, Romans 8:11, Titus 3:5, Ezekiel 36:27). Additional verses, including 2 Peter 1:21, Romans 15:16, and 1 John 5:6, underline the Spirit’s inspiring, sanctifying, and truth-bearing roles.

This comprehensive survey shows that the Holy Spirit fully possesses, shares, and bestows the divine nature as one who is neither a lesser deity nor an impersonal power, but truly God and co-equal with the Father and the Son. Together, the Old and New Testaments reveal one God–Father, Son, and Holy Spirit–fulfilling Deuteronomy 6:4 while opening the door to profound internal distinctions. First Corinthians 8:4–6 teaches that “one God” and “one Lord” apply to Father and Son, preserving monotheism and yet affirming personal distinction. Christ is acknowledged as God (John 20:28, Titus 2:13), the author of creation (John 1:3, Colossians 1:16), the object of worship (Philippians 2:10–11), and the eternal Creator (Hebrews 1:10–12). The Spirit is recognized as God (Acts 5:3–4) who sanctifies and leads believers (1 Corinthians 3:16–17, John 16:13). The “I AM” of Exodus 3:14, pointing to the Father, merges with the “I am” of Isaiah 43:10–11, anticipating the Son, and the Spirit’s divinity is seamlessly woven into the same narrative, culminating in Matthew 28:19, where the singular Name denotes one shared essence in three Persons.

Thus, Scripture reveals not a solitary monad but an eternal communion of Father, Son, and Holy Spirit, one divine essence subsisting in three eternally distinct Persons. Yet these Persons are not three independent modern “selves.” Each is a distinct subsistence, or hypostasis, within a superessential, superabundant, co-inhering, perichoretic unity. By intertwining the “I AM” of Exodus (the Father), the “I am” of Isaiah (the Son), and the Holy Spirit’s demonstrated divinity, we see that the Trinity offers the most coherent, biblically faithful account of the one LORD. In the New Testament, this becomes especially apparent when Jesus proclaims “Before Abraham was, I am” (John 8:58), unequivocally identifying Himself with the very Name of God revealed in Exodus and Isaiah and illustrating the fundamental theme of “One LORD, Three Persons: The Trinitarian ‘I AM’ from Exodus to the New Testament.”