When Mary gave her fiat at the Annunciation, the Word became flesh in her womb. In the taking of human flesh, God the Father prepared it, God the Holy Spirit formed it, and God the Son assumed it. He who was born in Bethlehem would later come to be born in the hearts of men. When Jesus was born in Bethlehem, it became a link between heaven and earth; God and man met there and looked each other in the face.
In becoming man, Jesus Christ did not lose anything of what he possessed as God. There was the mighty power of God in the movement of his arm, the infinite love of God in the beating of his heart and the unmeasured compassion of God towards sinners in his eyes. In the birth of Christ, God was manifest in the flesh. All the divine attributes of power and goodness, justice, love and beauty, were in him. When he acted and spoke, God became manifest to those who saw him and heard him and touched him.
The Eternal Word which assumed human nature was not created. On the other hand, his human nature was derived from Mary, in which the divine overshadowing of the Holy Spirit and the human consent of a Virgin, were most beautifully blended.
It is hard for a human person to fathom the humility that was involved in the Word becoming flesh. No humiliation on earth could compare to the emptying of God, in which he took on the form of man and accepted the limitations of humanity, such as hunger and persecution. This humiliation began in Nazareth when he was conceived, and continued until his final humiliation of death on the Cross.
On Christmas Day, the Savior was made manifest to the world. God the Father did not spare his Son; so much did he love mankind. “For God so loved the world that he gave his only Son, so that everyone who believes in him might not perish but might have eternal life” (John 3:16). That is the secret wrapped in the swaddling clothes.
Acknowledgments: Parts of this reflection were taken from The Life of Christ by Ven. Fulton Sheen.