How are we to think of the Incarnation? The New Testament does not encourage us to puzzle our heads over the physical and psychological problems that it raises, but to worship God for the love that was shown in it. For it was a great act of condescension and self-humbling. “He, who had always been God by nature,” writes Paul, “did not cling to his privileges as God’s equal, but stripped Himself of every advantage by consenting to be a slave by nature and being born a man. And, plainly seen as a human being, he humbled himself by living a life of utter obedience, to the point of death, and the death he died was the death of a common criminal” (Phil 2:6-8 Phillips). And all this was for our salvation. . . .
The crucial significance of the cradle at Bethlehem lies in its place in the sequence of steps down that led the Son of God to the cross of Calvary, and we do not understand it till we see it in this context. . . . The taking of manhood by the Son is set before us in a way which shows us how we should ever view it — not simply as a marvel of nature, but rather as a wonder of grace.
– J. I. Packer, Knowing God, Downers Grove, IL: InterVarsity Press, 1993; pp. 58-59.