The term hypostatic union is much easier than it sounds, but the concept is as profound as anything in the universe—the personal union of the eternal Son of God with our humanity.
The English adjective hypostatic comes from the Greek word hupostasis. The word only appears four times in the New Testament—maybe most memorably in Hebrews 1:3, where Jesus is said to be “the radiance of the glory of God and the exact imprint of his nature.” Here the author of Hebrews uses the word in reference to the oneness of God. Both the Father and the Son are of the same “nature.” Jesus is “the exact imprint of his nature.”
However, in early church discussions, as Greek speakers tried to find agreeable terms with those who spoke in Latin, the word hupostasis came to denote not the sameness in the Godhead (the one divine essence) but the distinctness (the three divine persons). So it began to be used to refer to something like the English word person.
The Personal Union of Jesus’ Two Natures
So “hypostatic union” may sound fancy in English, but it’s a pretty simple term. Hypostatic means personal. The hypostatic union is the personal joining of Jesus’ two natures in one person.
Jesus has two complete natures—one fully human and one fully divine. What the doctrine of the hypostatic union teaches is that these two natures are united in one person in the God-man. Jesus is not two persons. He is one person. The hypostatic union is the joining of the divine and the human in the one person of Jesus.
What Is the Significance?
Why bother with this seemingly fancy term? What good is it to know about this hypostatic union? At the end of the day, the term can go, but the concept behind the term is infinitely precious—and worshipfully mind-stretching.
It is immeasurably sweet—and awe-inspiring—to know that Jesus’ two natures are perfectly united in his one person. Jesus is not divided. He is not two people. He is one person. As the Chalcedonian Creed (451 A.D.) states, his two natures are without confusion, without change, without division, and without separation. Jesus is one.
This means Jesus is one focal point for our worship. And as Jonathan Edwards preached, in this one-person God-man we find “an admirable conjunction of diverse excellencies.” Because of this hypostatic, one-person union, Jesus exhibits an unparalleled magnificence. No one person satisfies the complex longings of the human heart like the God-man.
God has made the human heart in such a way that it will never be eternally content with that which is only human. Finitude can’t slake our thirst for the infinite. And yet, in our finite humanity, we are significantly helped by a point of correspondence with the divine. God was glorious long before he became man in Jesus. But we are human, and unincarnate deity doesn’t connect with us in the same way as the God who became human. The conception of a god who never became man will not satisfy the human soul like the God who did.
One Person, For Us
And beyond just gazing at the spectacular person of Jesus, there is also the amazing gospel-laced revelation that the reason Jesus became the God-man was for us. His fully human nature joined in personal union to his eternally divine nature is a permanent showcase that Jesus, in perfect harmony with his Father, is undeterrably for us. He has demonstrated his love for us in that while we were still sinners, he took our nature to his one person and died for us.