What is the hypostatic union?
The hypostatic union is the theological name for what happened at the incarnation — Jesus Christ is one person ("hypostasis") with two natures, divine and human, united without confusion, change, division, or separation (the Chalcedonian Creed, AD 451).
It guards two truths at once: Jesus really is God (not a man God adopted) and Jesus really is man (not God in a costume).
The two natures retain their own properties. As God, the Son is omniscient. As man, Jesus could ask, "Who touched me?" Both are true of the same person.
Why it matters: the cross can only save if the one dying is both. Only a man can pay the human debt; only God can pay the infinite debt. Jesus is both.
Original BibleDawn answer · reviewed 2026-06. Drafted with AI assistance and reviewed for accuracy.