|To save his people
The first step for the Son in God's plan of redemption was for him to enter our world as one of us. John's gospel says, "The Word"—the eternal Son—"became flesh" (John 1:14). This doesn't mean the Son stopped being God, or became a little less God (whatever that would be), for John's gospel is filled with testimony to the full deity of Jesus. Rather, the eternal Son of God was joined forever with genuine human nature, so that Jesus was—and still is—fully God and fully human in one person.
In other words, the Son became human by addition, not subtraction. He took on a human body, a human mind, and a human soul. Theologians sometimes express it like this: "Remaining what he was, he became what he was not." The term Christians use for the union of the eternal Son with human nature is incarnation.
If you're left wondering how the incarnation works, you're not alone. Wayne Grudem writes,
The fact that the infinite, omnipotent, eternal Son of God could become man and join himself to a human nature forever, so that infinite God became one person with finite man, will remain for eternity the most profound miracle and the most profound mystery in all the universe.1Each person of the Trinity had an active role in the incarnation. The Father sent the Son (Romans 8:3; Galatians 4:4) and the Son came willingly, "emptying himself," according to Philippians 2:7.
And the Holy Spirit? Well, it's only right that the most profound miracle in the universe starts with a miraculous conception, isn't it? The person Jesus, true eternal Son and true human, was conceived without a human father by the supernatural work of the Holy Spirit.
For Our Salvation
It's because of his miraculous conception that the human Jesus was morally pure (Luke 1:35). Unlike the rest of humanity conceived by ordinary means, Jesus did not inherit a sinful nature from Adam. This is an important detail in the fulfillment of the purpose of the incarnation. If Jesus came "to save his people from their sins," then he himself needed to be sinless. Only another human being, but one without any sin, even a sinful nature, could be an atoning sacrifice to bear our sins and die in our place. (We'll look more closely at how Jesus saves his people, including his atoning sacrifice, in the next post of this series.)
This is one reason our Saviour had to be a human being. But why did he have to be God incarnate? Because, for one, only someone who is both human and God could be the mediator who represents us to God and God to us (1 Timothy 2:5; John 14:9). What's more, because Jesus is God, he is able to accomplish everything he intends to do. He will surely save those who come to him; he can be an effective Savior because he is God.
The incarnation, then, was necessary for God to save us. The union of God and man in Jesus Christ stands at the very center of the Christian faith, because without it there would be no Christians—and no Christianity.
Definition of Chalcedon
The ancient Christians took the biblical data on the nature of the incarnate Son of God and formulated the Definition of Chalcedon, a statement of what all Christians must believe regarding the person of Jesus. Briefly, the Definition of Chalcedon teaches that Jesus has two natures, a human nature and a divine nature. His divine nature is just like God the Father's; his human nature is just like our human nature, except our human nature is sinful and his is not. In Jesus, the divine nature and human nature remain distinct yet united in one person.
Here are a few ways to learn more about the incarnation of the Son of God.
- Study John 1:1-18, Philippians 2:5-11, and Hebrews 2:14-18.
- Study the Definition of Chalcedon.
- Read up on the person of Christ in your favorite systematic theology. It's in chapter 25 of Wayne Grudem's Systematic Theology: An Introduction to Biblical Doctrine. Here's the section from Louis Berkhof's Systematic Theology. There's also a section on Christ's State of Humiliation which includes information on the incarnation.
- Listen to The Doctrine of the Incarnation by D. A. Carson.
- Listen to The Two Natures of Christ by Gerald Bray.
This post is the latest in a series of posts on truths every Christian woman should know. Here are the previous posts: