The Incarnation of Christ

Good News of Great Joy

Every Christmas we are reminded of the message that the angel of the Lord proclaimed to a group of lowly shepherds who were out in the field watching over their flock at night (v.8). In Luke 2:10-12 it is written,

“And the angel said to them, “Fear not, for behold, I bring you good news of great joy that will be for all the people. For unto you is born this day in the city of David a Savior, who is Christ the Lord. And this will be a sign for you: you will find a baby wrapped in swaddling cloths and lying in a manger.” (ESV)

What was so “good” about this news? What was so joyful about the announcement of this baby’s birth?

First, the good news of Christmas is that the baby who was born that day was the “Savior” (v.11). And this Savior was not just born, but born “unto you” (v.11). In other words, He was born for our sakes. It is the same language that is found in the Messianic prophecy found in Isaiah 9:6-7, where we read:

“For unto us a child is born, unto us a son is given: and the government shall be upon his shoulder: and his name shall be called Wonderful, Counselor, The mighty God, The everlasting Father, The Prince of Peace. Of the increase of his government and peace there shall be no end, upon the throne of David, and upon his kingdom, to order it, and to establish it with judgment and with justice from henceforth even for ever. The zeal of the Lord of hosts will perform this.” (King James Version, emphasis mine)

Second, the birth of Jesus was not only the birth of the Savior, but also the birth of One who was and is “Christ the Lord” (Luke 2:11). As God spoke through the prophet Isaiah hundreds of years before the birth of Christ, the child who was born “unto us,” and the son who was given “unto us” was none other than “the Lord,” the “mighty God.”

Only someone who is truly God and truly man in one person could accomplish our redemption from sin. Our debt of sin is infinite because every sin is committed against an infinitely holy God. And yet only someone who is also truly a man could die in the place of men. It is only in the person of Jesus Christ that such a Savior is to be found! As the Apostle Paul writes in 1 Timothy 2:5,

“For there is one God, and there is one mediator between God and men, the man Christ Jesus,” (ESV)

And so the manger of Christmas presupposes the cross of Good Friday. The purpose of the incarnation was that Jesus might die to save His people from their sins (Matthew 1:21) and rise from the dead on the third day for their justification (Romans 4:25).

Do you know the true joy of Christmas? It is only by faith in Jesus that the fear of judgment is replaced by the “great joy” of salvation from sin, and eternal life in Him.

B.B. Warfield on the Importance of the Incarnation of Christ

BB Warfield 2It has been said that justification by faith alone is the doctrine by which the church stands or falls. Likewise in his Institutes of the Christian Religion John Calvin similarly wrote that justification is “the main hinge on which religion turns” (Ford Lewis Battles translation, p.726). In other words, the doctrine of justification by faith alone is in some way the central doctrine of true Christianity.

Benjamin B. Warfield said something similar about another central Christian doctine – the doctrine of the two natures (God and man) in the one person of Christ. He writes,

“[T]he doctrine of the two natures is only another way of stating the doctrine of the Incarnation; and the doctrine of the Incarnation is the hinge on which the Christian system turns. No Two Natures, no Incarnation; no Incarnation, no Christianity in any distinctive sense.” (The Works of Benjamin B. Warfield, Vol. III, p.259)

Warfield calls the doctrine of the incarnation of Christ “the hinge on which the Christian system turns.” Why? Because without it there really is no Redeemer, and so no gospel as well. Without the truth of the incarnation of Christ, you may still have a system of doctrine that goes by the name “Christian,” but it will not be truly Christian (to use Warfield’s phrase) “in any distinctive sense.”

In other words, it would be “Christian” in name only, and would then be essentially no different at its core from any other religion known to man, all of which (except for the biblical gospel alone) basically boil down to one form or another of salvation by works. You can either hold to a salvation by works (by self!), or a salvation by a Redeemer. And the only Redeemer (in order to actually be the Redeemer of sinners) must be both God and man in one person.

As the Westminster Shorter Catechism (Q.21) puts it,

“The only Redeemer of God’s elect is the Lord Jesus Christ, who, being the eternal Son of God, became man, and so was, and continues to be, God and man in two distinct natures, and one person, forever.”

The doctrine of the incarnation of Christ, which we celebrate every Christmas, really is “is the hinge on which the Christian system turns.” Without it, there is no real Christianity.


John Owen on the Communicatio Idiomatum

Owen (Glory of Christ)The communicatio idiomatum (or the communication of properties) is one of the more important doctrines related to the incarnation of Christ, and yet it is not exactly one of the more well-known or commonly-discussed doctrines in our day.

The Westminster Confession of Faith, in its chapter entitled “Of Christ the Mediator” puts it this way:

“Christ, in the work of mediation, acts according to both natures, by each nature doing that which is proper to itself; yet, by reason of the unity of the person, that which is proper to one nature is sometimes in Scripture attributed to the person denominated by the other nature” (8.7).

That, for example, is why Acts 20:28 can speak of “the church of God, which he obtained with his own blood” (ESV, emphasis mine). Can God bleed? In the person of Christ, yes, but only according to His human nature. But because of the unity of His person, the Son of God can properly be said to have suffered, bled, and died.

The communicatio and some of its implications are helpfully summarized by Louis Berkhof:

“[The communicatio idiomatum] means that the properties of both, the human and divine natures, are now the properties of the person, and are therefore ascribed to the person. The person can be said to be almighty, omniscient, omnipresent, and so on, but can also be called a man of sorrows, of limited knowledge and power, and subject to human want and miseries. We must be careful not to understand the term to mean that anything peculiar to the divine nature was communicated to the human nature, or vice versa; or that there is an interpenetration of the two natures, as a result of which the divine is humanized, and the human is deified (Rome). The deity cannot share in human weakness; neither can man participate in any of the essential perfections of the Godhead.” (Systematic Theology, p.324)

In his book, The Glory of Christ, John Owen (1616-1683) explains how all of this relates to the earthly life, ministry, and death of Christ. He writes,

“The Lord Christ suffered and did many things both in his life and in his death as a human being. But all that he did and suffered as a human being was done and suffered by his whole person, even although what he did and suffered as a human being was not actually done and suffered by his divine nature. Because his human nature was part of his whole person, what he did as a human being could be said to have been done by God himself as God, e.g. God purchased his church ‘with his own blood; (Acts 20:28).” (p.43-44)

So we do not speak of the human nature of Christ dying for our sins, but of the death of Christ Himself (i.e. his whole person), according to His human nature. As Owen puts it, all that He did and suffered “was done and suffered by his whole person,” and yet also “not actually done and suffered by his divine nature.” Only this doctrine, properly understood, truly does justice to the incarnation of Christ, as well as to both His divine and human natures.

Christmas & the Cross

Boice WHTGGChristmas and the cross must go together. Without the cross, the manger is essentially meaningless.

In his book, Whatever Happened to the Gospel of Grace?, James Montgomery Boice writes,

Christmas by itself is no gospel. The life of Christ is no gospel. Even the resurrection by itself is no gospel. The Good News is not just that God became man, nor that God has spoken in Christ to reveal a proper way of life for us, nor even that death, our great enemy, has been conquered. The Good News is that sin has been dealt with, that Jesus suffered its penalty for us as our representative, and that all who believe in him can look forward confidently to heaven” (p.105).

The story of the incarnation of Christ that we rightly focus on every year at Christmas, as wonderful as it is, saves no one apart from the cross. The life of Christ, as important as it is, saves no one apart from the cross. Christ certainly calls His people to follow Him (Mark 1:17; 8:34), and so to obey His commands and to emulate His example, but without the cross, the “right way of living” saves no one – it would still just lead to death.

The purpose of Christ’s incarnation was so that He would save His people from their sins (Matthew 1:21), and that means, first and foremost, that He was born so that He might die in the place of sinners.

The Supreme Mystery of the Gospel


“[T]he supreme mystery with which the gospel confronts us . . . .lies not in the Good Friday message of atonement, nor in the Easter message of resurrection, but in the Christmas message of Incarnation. The really staggering claim is that Jesus of Nazareth was God made man – that the second person of the Godhead became the “second man” (1 Cor 15:47), determining human destiny, the second representative head of the race, and that he took humanity without loss of deity, so that Jesus of Nazareth was as truly and fully divine as he was human.” (J.I. Packer, Knowing God, p.53)