Christmas celebrates the face that God himself broke in to human history in order to restore a fallen humanity and a broken world. I offer the following passage from On the Incarnation by Athanasius, the fourth-century bishop of Alexandria, as a Christmas meditation.
For this purpose, then, the incorporeal and incorruptible and immaterial Word of God entered our world. In one sense, indeed, He was not far from it before, for no part of creation had ever been without Him Who, while ever abiding in union with the Father, yet fills all things that are. But now He entered the world in a new way, stooping to our level in His love and Self-revealing to us. He saw the reasonable race, the race of men that, like Himself, expressed the Father’s Mind, wasting out of existence, and death reigning over all in corruption. He saw that corruption held us all the closer, because it was the penalty for the Transgression; He saw, too, how unthinkable it would be for the law to be repealed before it was fulfilled. He saw how unseemly it was that the very things of which He Himself was the Artificer should be disappearing. He saw how the surpassing wickedness of men was mounting up against them; He saw also their universal liability to death. All this He saw and, pitying our race, moved with compassion for our limitation, unable to endure that death should have the mastery, rather than that His creatures should perish and the work of His Father for us men come to nought, He took to Himself a body, a human body even as our own. Nor did He will merely to become embodied or merely to appear; had that been so, He could have revealed His divine majesty in some other and better way. No, He took our body, and not only so, but He took it directly from a spotless, stainless virgin, without the agency of human father—a pure body, untainted by intercourse with man. He, the Mighty One, the Artificer of all, Himself prepared this body in the virgin as a temple for Himself, and took it for His very own, as the instrument through which He was known and in which He dwelt. Thus, taking a body like our own, because all our bodies were liable to the corruption of death, He surrendered His body to death instead of all, and offered it to the Father. This He did out of sheer love for us, so that in His death all might die, and the law of death thereby be abolished because, having fulfilled in His body that for which it was appointed, it was thereafter voided of its power for men. This He did that He might turn again to incorruption men who had turned back to corruption, and make them alive through death by the appropriation of His body and by the grace of His resurrection. Thus He would make death to disappear from them as utterly as straw from fire.
The Word perceived that corruption could not be got rid of otherwise than through death; yet He Himself, as the Word, being immortal and the Father’s Son, was such as could not die. For this reason, therefore, He assumed a body capable of death, in order that it, through belonging to the Word Who is above all, might become in dying a sufficient exchange for all, and, itself remaining incorruptible through His indwelling, might thereafter put an end to corruption for all others as well, by the grace of the resurrection. It was by surrendering to death the body which He had taken, as an offering and sacrifice free from every stain, that He forthwith abolished death for His human brethren by the offering of the equivalent. For naturally, since the Word of God was above all, when He offered His own temple and bodily instrument as a substitute for the life of all, He fulfilled in death all that was required. Naturally also, through this union of the immortal Son of God with our human nature, all men were clothed with incorruption in the promise of the resurrection. For the solidarity of mankind is such that, by virtue of the Word’s indwelling in a single human body, the corruption which goes with death has lost its power over all. You know how it is when some great king enters a large city and dwells in one of its houses; because of his dwelling in that single house, the whole city is honored, and enemies and robbers cease to molest it. Even so is it with the King of all; He has come into our country and dwelt in one body amidst the many, and in consequence the designs of the enemy against mankind have been foiled and the corruption of death, which formerly held them in its power, has simply ceased to be. For the human race would have perished utterly had not the Lord and Savior of all, the Son of God, come among us to put an end to death.
Let us remember that the Christ Child laid in a wooden manger is the same God-Man hung on a wooden cross in our place. Merry Christmas.
You can read the entire text of On the Incarnation here.