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How the Early Church Found the Trinity in the Old Testament

Graphic with the word Trinity and a black and white sketch picture.

The elderly gentleman who confronted me after my adult catechesis class did not look particularly happy with me. “What do you mean, the Trinity isn’t in the Bible?” he asked, opening his well-worn King James Bible to 1 John 5:7–8 and stabbing a finger down at the page. “Don’t you see right here? Father, Word, and Holy Spirit!”

My parishioner had taken issue with my claim that the doctrine of the Trinity—namely, that there is one God who has eternally existed as the three persons of the Father, the Son, and the Holy Spirit—is not explicitly taught in sacred Scripture. Now, I knew, he was going to be even less happy with me as I prepared to gently explain that the KJV rendering of 1 John 5:7–8, following the so-called Comma Johanneum, is almost certainly a later addition to the text of this epistle and rightly relegated to the footnotes of nearly all modern Bible translations.

What prompted this well-meaning gentleman’s question was, in fact, an issue of supreme importance for all Christians: What is the relationship between the Bible and the doctrine of the Trinity? After all, the great trinitarian controversies that led to the orthodox definition of the Trinity at the first two ecumenical councils did not take place until the fourth century, hundreds of years after the books that comprise the New Testament were written. Small wonder, then, that at the time of the Reformation, some Anabaptists went so far as to discard the doctrine of the Trinity as incompatible with the teaching of the Bible. An appeal to matters of textual criticism in 1 John would do little to confirm the matter of my orthodoxy in this parishioner’s mind.

The key word in my statement, I reminded him, was that the Bible does not explicitly teach the doctrine of the Trinity. That being said, not only are all the ingredients or raw materials for that doctrine present in Scripture, but a reading of the Bible that aims simultaneously to preserve monotheism and to acknowledge the deity of Christ (not to mention the deity of the Holy Spirit) alongside the Father actually demands such a doctrine.

If I had the time to give him a more complete response, however, I would approach this question from still another angle. By training, I am a historical theologian whose work has focused on the writings of the church fathers of the second and third centuries. In my research, I have been struck time and again by how those early Fathers articulated their emerging understanding of unity and diversity within the Godhead by appealing to a most unlikely source: the Old Testament. In this article, I will briefly describe three aspects of the Old Testament that are unknown to or under-appreciated by many modern readers—but were nevertheless critical to early Christians’ developing understanding of the Trinity.

We begin with a brief overview of the place of the Old Testament in early Christian thought.

Overview: The Old Testament in early Christianity

The Old Testament, which comprised the Scriptures of Jesus’s first followers, was of course the natural place for early Christian reflection on Christ and on the nature of his relationship with God the Father. According to Luke’s Gospel, this phenomenon can be traced back to the resurrected Christ himself. As Luke tells us, Jesus appeared to two of his followers on the road to Emmaus. When they did not initially recognize him, Jesus, “beginning with Moses and all the prophets, interpreted to them the things about himself in all the scriptures” (Luke 24:27). Similarly, the Apostle Paul reminded the Corinthians, “I delivered to you as of first importance what I also received: that Christ died for our sins according to the Scriptures, that he was buried and that he was raised on the third day according to the Scriptures” (1 Cor 15:3–4).

Those who held to the position that Jesus Christ was at the very center of Israel’s Scriptures faced the challenge of reconciling how their belief in Christ somehow sharing in the identity of Israel’s God nevertheless did not undermine their foundational commitment to monotheism. Lambasted by non-believing Jews on the one hand, and pressured by Marcionites eager to jettison the Old Testament on the other, those Christians who aimed to hold together their belief in the truth of the Old Testament and their faith in the divinity of Christ had no choice but to demonstrate, from the words of the Old Testament themselves, how these seemingly contradictory positions could be reconciled.

Indeed, by the middle of the second century, one Roman Christian could boldly make the claim, following a citation of Old Testament passages, that

Scripture declares that the Son was begotten of the Father before all creatures, and everybody will admit that the Son is numerically distinct from the Father!1

How, though, could this possibly be? How could the Old Testament, of all things, possibly be used as evidence for emerging trinitarian theology?

At risk of oversimplifying, critical scholarship has traditionally rejected the notion that biblical exegesis and the doctrine of the Trinity have anything to do with one another; the latter is frequently cast as a development owing more to the influence of Greek philosophy than anything resembling ancient Israelite religion. The church fathers, though, seemed to be convinced that the Old Testament was the real source of their trinitarian theology—and this fact should push us, especially those of us who are heirs to the faith bequeathed to us by said fathers, not to dismiss such an influence out of hand. While a full analysis of the Old Testament’s contribution to trinitarian theology is beyond the scope of this blog post, the following three ideas were particularly influential in the exegetical approach of the early church fathers.

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Divine conversations: person-centered reading

The New Testament writers presuppose that the Old Testament, when rightly understood, spoke prophetically or typologically about Christ. While the primary approach the New Testament writers take is that of the fulfillment of prophecy, one less frequent but particularly intriguing mode of argument concerns Old Testament dialogue that was reread as a conversation between or concerning multiple divine persons. Careful attention to the details of such dialogical passages, the early Christian writers believed, in fact demanded precisely such a reading.

The Gospels, for example, present just such a person-centered reading strategy that has implications for how the Old Testament could be read through the lens of divine dialogues. In Mark 12:35–37, Jesus is debating the scribes in the Temple concerning the right interpretation of David’s words in Psalm 110:1,

The Lord said to my Lord, “Sit at my right hand, until I put your enemies under your feet.” (Mark 12:36)

To the scribes who believed that the Messiah was the son of David, Jesus asks, “David himself calls him Lord; so how can he be his son?” (Mark 12:37). The person to whom the dialogue recorded in Psalm 110:1 is spoken, Jesus is claiming, is referred to by David as “my Lord,” indicating that he is much greater than simply the son of David, a fact which is underscored by the rest of Psalm 110. Thus, Jesus’ interpretation of Psalm 110:1 highlights the possibility of reading the Old Testament as dialogue to or about multiple divine persons.

Hebrews elevates such a person-centered reading strategy (sometimes referred to in scholarly literature as prosopological exegesis) to a more sophisticated level. Across a catena of Old Testament quotations (Heb 1:5–14), the author of Hebrews seeks to establish that Christ is superior to the angels. He then proceeds to lay out a series of quotations that he intends us to read as spoken by the Father to or about the Son: “For to which of the angels did God ever say … ?” (Heb 1:5).

Thus, when the psalmist records the words, “You are my Son, today I have begotten you” (Ps 2:7), the author of Hebrews invites us to read this statement not through the lens of the historical moment of the enthronement of a Davidic king but rather through the lens of the Father speaking to the Son in what Matthew Bates calls a “theodramatic” setting in which this intra-divine dialogue takes place.2 More precisely, Bates continues, Psalm 2:7 is actually a report of earlier speech (“I will tell of the decree: the Lord said to me”); the Son is therefore reporting the speech of God the Father to him at some previous time, suggesting that while the “primary” setting in the theodrama is the enthronement of the Son following his ascension, there is also a “secondary” theodramatic setting from before the creation of the world.3

Thus, the emerging idea of the Son’s pre-existence can be glimpsed through a person-centered reading of Psalm 2:7, which the author of Hebrews reinforces with still further examples of Old Testament dialogues being cast as the speech of the Father to the Son (e.g., Heb 1:8–13; cp. Ps 45:6–7; Ps 102:25–27) or as the Son to the Father (e.g., Heb 2:11–13; cp. Ps 22:22; Isa 8:17–18). Such was the effect of the kind of interpretation on early Christian christological and trinitarian theology that this interpretive method would be further exploited by Christians such as Justin Martyr, Irenaeus of Lyons, and Tertullian of Carthage in the second and third centuries as they sought to understand how best to articulate the unity and diversity of the Godhead.4

Divine doublets: two powers in heaven

Another aspect of the Old Testament that early Christian writers appealed to for their doctrine of the Trinity concerned the existence in Scripture of so-called “two powers” texts. Already the focus of Hellenistic Judaism, both early Christians and Jews of the rabbinic period sought to interpret these texts in ways that could take the biblical text seriously while still preserving their belief in the unity of God.

Some of these two powers texts were dialogical passages that provided fodder for the kind of careful exegesis we are attempting to perform here. For example, as we saw above, when the psalmist writes, “The Lord said to my Lord: ‘Sit at my right hand, until I make your enemies your footstool’” (Ps 110:1), there are two “lords” in view, a potential problem that could be resolved by viewing this as a dialogue between two divine persons within the Godhead. Likewise, what were exegetes to make of the reference to two different characters called “God” in Psalm 45:6–7? Person-centered exegesis again provided the solution, with the Holy Spirit theodramatically speaking these words to the Son concerning the Father.5

“Two powers” texts did not, however, have to be exclusively dialogical in nature. Take, for instance, Genesis 19:24: “Then the Lord rained on Sodom and Gomorrah sulfur and fire from the Lord out of heaven.” The twofold reference to “the Lord,” something of an oddity in the text, is exploited by Justin and other Christian exegetes as evidence of the distinct existence of God the Father and God the Son.6

By building upon pre-existing Jewish notions of “two powers in heaven,” Justin and his successors were able to further use the Old Testament in support of emerging trinitarian doctrine. This conclusion was supremely important for the early church as it sought to defend the Old Testament against Marcion and his followers. As Oskar Skarsaune writes,

Having a Jew admit that that OT knows of a Second God, messenger of God the Father, bearing the name Jesus–that would be something to bring against Marcion and his disciples!7

By demonstrating that the Old Testament, when rightly understood through the eyes of Christian faith, in fact provided a firm foundation for belief in the Triune God, the church fathers claimed the Old Testament as the Church’s Bible.

Divine theophanies: bringing God to earth

A third aspect of how the Old Testament came to be used as a source for trinitarian theology concerns the visible manifestations of God—the theophanies—recorded in its pages. To return again to Justin, these theophanies were not, as one would likely have thought, appearances of God the Father, but rather the actions of the pre-incarnate Christ.

Recall, again, that Marcion aimed at rejecting the Old Testament, believing that only with the incarnation of Christ was the true God made known. For Justin, however, Jesus is truly present in the Old Testament through his pre-incarnate appearances: visiting Abraham at Mamre (Gen 18–19), wrestling with Jacob (Gen 32), speaking to Moses through the burning bush (Ex 3).8

For Justin, as for many early Christian writers influenced by the prevailing philosophical climate of Middle Platonism, it was necessary to preserve the absolute transcendence of “the one, unbegotten, ineffable God.”9 How, then, to make sense of what appear to be visible manifestations of this unbegotten and ineffable God to the people of God in the Old Testament? Enter the pre-incarnate God the Son, the Logos of God, mediator between God and man. Whereas God the Father cannot be said to be the referent of any of the actions ascribed to “God” within human salvation history, God the Son, as the angel or messenger of the Father, who would become incarnate by the Holy Ghost and the Virgin Mary, could be the one encountered by God’s people throughout the Old Testament.

Again, the New Testament itself plants the seeds for such an approach. Jude, for instance, says that Jesus “saved a people out of the land of Egypt, presiding over the Exodus” (Jude 5). It is only a short jump from such a verse to Justin’s claim that Moses “received mighty power from Christ who spoke to him in the form of fire, and went down and led out the people having done great and marvelous things.”10 Likewise, when the Apostle Paul commented that Jesus was the “spiritual Rock” from which the Israelites drank from in the wilderness (1 Cor 10:4), he opened the door for finding Christ’s presence not simply in the Old Testament theophanies but in a mystical and sacramental way as well.

To take just one famous example: Melito of Sardis, in his On the Passover, connected Christ with the Paschal lamb and, indeed, much of the Old Testament:

This [Jesus] is the Pascha of our salvation: this is the one who in many people endured many things. This is the one who was murdered in Abel, tied up in Isaac, exiled in Jacob, sold in Joseph, exposed in Moses, slaughtered in the lamb, hunted down in David, dishonored in the prophets.11

Thus, even beyond those physical theophanies in which the pre-incarnate Christ appeared to Old Testament saints, types of the coming Christ can in fact be seen throughout the Old Testament.


My parishioner’s instinct to defend the idea that the Trinity is in fact a biblical idea was a good one. But his approach, to try and find a proof text or two that would explicitly set out this doctrine, was misguided. As this article has demonstrated, the early church fathers recognized that the presence of the Father, the Son, and the Holy Spirit is in fact woven throughout the contours of the Old Testament. Through the early church fathers’ interpretation of dialogical passages, “two powers” texts, and theophanies, a form of biblical reading emerged that would greatly contribute to the development of christological (and, by extension, trinitarian) doctrine, giving shape to an understanding of unity and diversity within the Godhead that would shape later creedal formulations.

Thus, while it would no doubt be a mistake to say that such an approach to Old Testament interpretation was the only important factor in the development of Trinitarian theology, Christians should be confident that biblical exegesis was indeed very much at the heart of this central doctrine from the very beginning. The Trinity is, indeed, very much in the Bible—perhaps far more than most Christians have ever suspected.

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  1. Justin Martyr, Dial. 129.3 (trans. Falls).
  2. See Bates, Birth of the Trinity, 34–35.
  3. Bates, Birth of the Trinity, 67–68.
  4. See Hughes, The Trinitarian Testimony of the Spirit.
  5. See Hughes, How the Spirit Became God.
  6. Justin Martyr, Dial. 56.12, 56.23; cp. Irenaeus, Against Heresies 3.6.1. Combined with Psalm 110:1 and Psalm 45:6–7, these three passages almost certainly circulated together as part of a “two powers” testimonia collection.
  7. Skarsaune, The Proof from Prophecy, 211.
  8. See, e.g., Justin Martyr, Dial. 126–127; 1 Apol. 62–63.
  9. Justin Martyr, Dial. 126.2 (trans. Falls).
  10. Justin Martyr, 1 Apol. 62. (trans. Barnard).
  11. Melito of Sardis, On Pascha, trans. Stewart-Sykes, (Yonkers, NY: St. Vladimir’s Seminary Press, 2016), 69.
Written by
Kyle Hughes

Kyle R. Hughes (PhD, Radboud University, Nijmegen) is the author of three books, including How the Spirit Became God and Teaching for Spiritual Formation, as well as several peer-reviewed journal articles on patristic theology and on Christian education. His current book project, Scripting the Son, explores the intersection of Old Testament interpretation and the development of Christology in the second and third centuries. Kyle also serves as the Director of Catechesis at Christ the King Anglican Church in Marietta, GA. Follow him at or on Twitter @KyleRHughes10.

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Written by Kyle Hughes