“The mystery of Christ runs the risk of being disbelieved precisely because it is so incredibly wonderful. For God was in humanity. He who was above all creation was in our human condition; the invisible one was made visible in the flesh; he who is from the heavens and from on high was in the likeness of earthly things; the immaterial one could be touched; he who is free in his own nature came in the form of a slave; he who blesses all creation became accursed; he who is all righteousness was numbered among transgressors; life itself came in the appearance of death.”
-St. Cyril of Alexandria, On the Unity of Christ
Cyril calls the Incarnation many things: “Mysterious,” “truly wonderful,” “incomprehensible,” “profound,” a “strange and rare paradox.” Turn to almost any page in his treatise and you will find him extolling the many and varied virtues of Christ’s “holy, wonderful, and truly amazing birth and life.” And the reason for this rampant rejoicing, this extravagant ecstasy, this passionate, persistent, poetic praise? Simply this: “he who is and exists from all eternity, as he is God, underwent birth from a woman according to the flesh;” in the Incarnation, “God was in humanity.”
To Cyril, the Christian faith hangs on the fact that the being named Jesus, who was born into a dirty stable from a human mother, who walked with dusty feet along the paths of Judea, who was hungry, and thirsty, and tired, was and is utterly and completely God and utterly and completely man. In the being named Jesus of Nazareth we see God and man in an inseparable union.
And the picture of God painted by the Old Testament demonstrates how stunning, how incomprehensible, how graceful and marvelous such a union is. God laid the foundations of the world. He determined its measurements. He has commanded the morning since there was a morning to command. He has created marvelous things, including man from the dust of the ground. He speaks out of the whirlwind, out of the storm, out of a blinding, radiant cloud.
His arm is strong, his voice is thunderous, his place is on high. He is a pillar of fire that lights up the dark. He is waited on by seraphim who eternally sing his praise. He is All-Sufficient, Lord of Hosts, the Holy One of Israel. His very name is so holy that it cannot even be spoken. He is God, and not a man.
And then the Most High God is born in a cave, below even the ground. The God that spoke out of the whirlwind cries out from an empty feeding trough. The Shepherd of Israel is chided by his parents. The creator of heaven and earth learns to help his father craft chairs and tables. The All-Sufficient One hungers and thirsts, and falls from weariness. The Lord of Hosts is a wanderer, with nowhere to lay his head. One of his names is spoken with scornful familiarity by those who dare not utter the other.
“God was in humanity.” Every word here is vitally important to the Christian faith. God, in the full sense of the term, in all majesty, power, and divinity, fully entered into humanity in a way that had never happened before. God was born of a woman. God was truly human.