From the Word
1 In those days a decree went out from Caesar Augustus that all the world should be enrolled. 2 This was the first enrollment, when Quirini-us was governor of Syria. 3 And all went to be enrolled, each to his own city. 4 And Joseph also went up from Galilee, from the city of Nazareth, to Judea, to the city of David, which is called Bethlehem, because he was of the house and lineage of David, 5 to be enrolled with Mary, his betrothed, who was with child. 6 And while they were there, the time came for her to be delivered. 7 And she gave birth to her first-born son and wrapped him in swaddling cloths, and laid him in a manger, because there was no place for them in the inn.
Luke 2:1–7, RSV
He was born of the virgin Mary. There is no deception here, for the Word clearly states that it was an actual birth. Mary’s experience was not different from that of other women, so that the birth of Christ was a real natural birth, Mary being his natural mother and he being her natural son. But she brought forth without sin, without shame, without pain and without injury, just as she had conceived without sin. The curse of Eve did not come upon her, where God said: “In sorrow shalt thou bring forth children.”
Grace does not interfere with nature and her work, but rather improves and promotes it. I mention this that we may be grounded in the faith and know that Jesus was a natural man in every respect just as we are, the only difference being in his relation to sin and grace, he being without a sinful nature. It is a great comfort to us that Jesus took upon himself our nature and flesh. Therefore we are not to take away from him or his mother anything that is not in conflict with grace, for the text clearly says that she brought him forth, and the angels said, Unto you he is born.
How could God have shown his goodness in a more sublime manner than by humbling himself to partake of flesh and blood, so that henceforth even that can be regarded godly, honest and pure, which in all men is ungodly, shameful and impure? These are real miracles of God, for in no way could he have given us stronger, more forcible and purer pictures of chastity than in this birth. When we look upon this birth, and reflect how the sublime Majesty moves with great earnestness and inexpressible love and goodness upon the flesh and blood of this virgin, we see how all evil lust and every evil thought is banished. No woman can inspire such pure thoughts in a man as this virgin; nor can any man inspire such pure thought in a woman as this child. If in reflecting on this birth we recognize the work of God that is embodied in it, only chastity and purity spring from it.
Martin Luther and John Sander, Devotional Readings from Luther’s Works for Every Day of the Year (Rock Island, IL: Augustana Book Concern, 1915), 453–454.