The Key to the Trinity: “The One True God”

To recap the previous article, Jesus called the Father the only true God and said that the Father was greater than He (Joh 17:3; 14:28). Some argue, therefore, that Jesus’ own words upend the doctrine of the triunity of God, and any talk of three Persons in one God is unbiblical.

In response, we reminded ourselves of our duty to believe whatever these two verses say, and to establish what they say by interpreting them in the context of the whole Gospel. The whole book is Christ’s Word just as much as the quotations of Christ it records.

When we do so, we begin to detect a pattern. We can call it the pattern of both. Twice in the prologue John both identifies the Son as God and distinguishes Him from God (1:1,18). Partway through the Gospel Jesus does the same, distinguishing Himself from – and identifying Himself as – the one and only God of Israel (8:54,58). Now, as we turn in this article to the end of the book, we’ll see John use the pattern again.

“My God”

We’ll also see another feature emerge – the book’s overall structure. John hasn’t just bookended the prologue with Christ’s deity (1:1,18) but his whole Gospel. The climax of the main body of his work is Thomas saying, “My Lord and my God” (20:28).[1] This is the kind of expression an Israelite would say to Yahweh, or heaven-dwellers to God the Father (Psa 99:8; Rev 4:11).[2] Thomas says it to Jesus Christ. Jesus is God at the beginning and end of this Gospel (1:1; 20:28).[3]

Anti-trinitarians have ingenious ways of getting around the plain sense of this text. Most of them are refuted by noting that

  • Thomas is a monotheistic Jew;
  • Jesus’ sudden appearing and supernatural knowledge imply His deity (v27);
  • Thomas is answering Jesus (not looking up to heaven);
  • Far from rebuking Thomas, Jesus endorses his faith (v29).

A more sincere objection points out that Thomas isn’t the first person to say “My God” in the passage. A few verses earlier, Jesus says the same words to His God, the Father (v17). Jesus is Thomas’ God, sure, but the Father is Jesus’ God. “See,” this view says, “it all fits with 14:28 and 17:3. As God’s Son, Jesus is divine in nature. But the Father alone is the one true God, the highest in rank. Why else would the Son call Him ‘my God’?”

Sadly, this interpretation fails to detect John’s pattern, the one he expects us to recognize from the Gospel’s opening verse.[4] John is again identifying Jesus as God in the same breath that he distinguishes Him from God. The words “my God” spoken to Christ establish His deity; the words “my God” spoken by Christ distinguish His Person – He is not the Father but the Son.

“But John,” we ask, “how can the Son call the Father His God if the Son is equal with the Father?” An exasperated John might reply: “Didn’t you read my prologue? Haven’t I already explained that the Son who is God became man?”

It’s just like what we saw in the article on Hebrews 1:8-9. To save us, the Son had to become a perfect man, obedient to every commandment, having no other gods before Yahweh. When Jesus calls the Father His God, He’s not diminishing His deity but expressing His humanity. Jesus is God, who has God, as His God. And because He will remain a man for all eternity, He will always – even in heaven – have God as His God (Rev 3:12). Far from signaling some inferiority on Christ’s part, the two instances of “my God” in John 21 powerfully convey that there are two Persons in one God, and that one of those Persons (the Son) is both God and man.[5]

“The Only True God”

It’s time to return to 17:3 and 14:28. But as we do, we must not forget the lessons we’ve learned. The whole structure of John’s Gospel is designed to defend – not diminish – Christ’s deity and humanity. And all the way through, John has deployed the both-pattern, an efficient strategy for communicating both unity in the one God and distinction in Persons. Yet some insist that when Jesus calls the Father the only true God, He’s not only excluding false pagan gods but also Himself.

But observe:

  • At minimum, 17:3 affirms monotheism, a crucial component of the triunity doctrine.
  • Jesus does not say that the Father alone is the only true God.[6]
  • The both-pattern re-emerges: eternal life is to know God the Father and Jesus Christ. See what this pairing implies? Who else could place his name there but One who is Himself God? Eternal life is to know God … eternal life is to know Christ.
  • Christ is the incarnate Son. As a man praying to His God, it is not only appropriate but reassuring to hear Him acknowledge the Father as the only true God. How else would we expect the perfect Man to pray?
  • Because eternal life is to know God, it is something only God can give. Yet the Son has authority to give it, just like the Father (17:2).
  • John is not afraid to call Christ “the true God” elsewhere (1Jn 5:20).[7]

Still unsure? Try turning the tables on your doubts. If 17:3 means that the Father alone is the true God, yet 20:28 says Jesus is God, then what kind of “god” does that make Jesus to be? Either a false god, or a separate one. If the former, then Jesus endorses Thomas’ worship of a false god. If the latter, then Thomas (and all Christians, 2Pe 1:1) worship two gods, in contradiction to the monotheism of 17:3![8]

The only way to hold on to all of Christ’s word in John’s Gospel is to grasp that both the Father and the Son are the one true God. There is nothing in 17:3 that contradicts this interpretation, and there is everything in the whole Gospel to support it. Our only other options are polytheism (Father and Son are separate gods) or to deny Christ’s deity. The Word of God constrains us.

“The Father Is Greater”

But someone will object: “You still haven’t touched on 14:28, and what about the fact that in 17:3 the Son is sent? We never read of the Father being sent by the Son.”

That’s true: the Father sends, the Son is sent. The Father gives the Son authority to bestow eternal life (17:2), not the other way around. John has already taught us how to understand this pattern as well, by teaching us that the Son is eternally begotten by the Father (1:14,18). I’ll try to address this in a later article.

Some believe it is this eternal begetting of the Son that lies behind Christ’s words, “The Father is greater than I” (14:28). A more likely explanation is that of Jesus’ humanity: “Equal to the Father as touching His Godhead, and inferior to the Father as touching His manhood.”[9]

The best view appeals not only to Christ’s incarnation but to the humiliation it entailed. The One who was equal with God humbled Himself to become a servant (Php 2:6-7).[10] A servant is not greater than his master (Joh 13:16). The Lord’s going away would unlock such blessings for the disciples (14:12,16), and restore such blessedness to the Lord, that it would be shortsighted selfishness on their part to begrudge His exaltation back to the glory and presence of the Father (17:5):

“He would no longer be walking the dusty roads of Galilee, surrounded by sin and sickness and misery. He would no longer be the subject of attack and ridicule by legions of scribes and Pharisees. Instead, He would be at the right hand of the Father in heaven itself. So we see that the term ‘greater’ speaks to the position of the Father in heaven over against the position of the Son on earth.”[11]

Once again, John requires us to believe both: the Father is greater than the Son (14:28), and the Son is equal to the Father (5:18; 10:30; Php 2:6). Each of the three views above enables us to believe both. But if we take 14:28 to mean that Jesus is not as fully God as the Father, we are silencing some texts in favor of others, in which case it is not the Trinity that’s unbiblical but those who deny it.

[1] All Scripture quotations in this article are from the ESV.

[2] Murray J. Harris, Jesus as God: The New Testament Use of Theos in Reference to Jesus (Eugene, OR: Wipf & Stock, 2008), 129.

[3] Harris, 127-29.

[4] Robert M. Bowman and J. Ed Komoszewski, Putting Jesus in His Place: The Case for the Deity of Christ (Grand Rapids, MI: Kregel Publications, 2007), 142-44.

[5] Another objection is that according to 20:31, John wants us to believe Jesus is the Son of God, not God. But for John, Jesus’ sonship shows His equality with God (5:18; 19:7). See Harris, Jesus As God, 125. Others think the word “my” empties the word “God” of significance. But see Harris, 122.

[6] Peter van Mastricht, Theoretical-Practical Theology, Volume 2: Faith in the Triune God, ed. Joel R. Beeke, trans. Todd M. Rester (Grand Rapids, MI: Reformation Heritage Books, 2018), 532-33, 560-61.

[7] Robert W. Yarbrough, 1-3 John, Baker Exegetical Commentary on the New Testament (Grand Rapids, MI: Baker Academic, 2008), 320.

[8] James White, The Forgotten Trinity (Minneapolis, MN: Bethany House Publishers, 1998), 91-92.

[9] The Athanasian Creed. See Wyatt Graham, “Is the Father Greater than the Son?” The Gospel Coalition, November 16, 2021,

[10] D.W. Gooding, In the School of Christ: A Study of Christ’s Teaching on Holiness, John 13-17 (Grand Rapids, MI: Gospel Folio Press, 1995), 67.

[11] White, The Forgotten Trinity, 90.