Why did Jesus become human?
I answered this question myself recently while celebrating The Lord’s Supper: he came to die. It’s an answer that’s most certainly correct. Hebrews 10:5-7 gives us a window into Jesus’ mind before the incarnation: “When Christ came into the world, he said, ‘Sacrifices and offerings you have not desired, but a body have you prepared for me; in burnt offerings and sin offerings you have taken no pleasure. Then I said, ‘Behold, I have come to do your will, O God, as it is written of me in the scroll of the book.’” Jesus came to fulfill prophecy and to do God’s will by offering himself as a better sacrifice.
It’s a good answer, but it’s incomplete. “We tend to hurry over the incarnation, seeing it as a necessary step to get Jesus to the cross,” observes Chris Armstrong in his book Medieval Wisdom for Modern Christians.
In his book Theological Retrieval for Evangelicals, Gavin Ortlund draws on the work of Irenaeus, Anselm, and Athanasius to suggest that there’s more to Jesus’ incarnation than first meets the eye.
The Incarnation Changes Everything
The incarnation marks a basic change to reality. “At creation, something other than God emerges (thus there are now two things); at the incarnation, God now unites himself to this second thing (thus those things become one) … How could such a pivotal event not fundamentally alter human nature and all created reality with it?”
At the incarnation, the very nature of reality changes. It’s the first significant change in the nature of reality since creation. God and creation come together and will stay that way for eternity.
Jesus’ Whole Life is Substitutionary
Not only that, but Jesus’ entire life — not just his death — was in some sense substitutionary. “His death is the climactic expression of a process already begun,” writes Ortlund. Or, as Tim Keller often puts it, “Christ lived the life we should have lived; Christ died the death we should have died.”
Ortlund cautions us against pitting Christ’s substitutionary death and his broader incarnate work against each other. Each should enhance the other. “Ultimately, Jesus’s great saving work is a unity (as much as his person is a unity) whose components can be distinguished but never divided.”
The manger gives us a better view of the cross, and the cross gives us a better view of the manger.
And There’s More
The more I learn about Jesus, the more I realize how much I have to learn. To borrow an image Alec Motyer, from I’m like a spelunker who explores one cave and masters it, only to find that it leads to another cave, and another one after that.
The more we look at Jesus, the more there is to see. The more reason we have to worship. Our understanding will never capture his work or his glory.
Why did Jesus become human? To become the second Adam, the first man of the new creation, our mediator, and our covenant head. He came to unite himself with us, and to live and die in our place.
We’ll spend eternity exploring this and more — not just exploring but worshiping the Christ who was born. O, come let us adore him!
