A paraphrase of Luther, quoting Saint Bernard:
Three Christmas miracles:
1. God became a man.
2. A mother remained a virgin.
3. Mary had the faith to accept that these mysteries were being accomplished in her.
Luther goes on to say:
"The last is not the least of the three. The virgin birth is a mere trifle for God; that God should become man is a greater miracle; but most amazing of all is that this maiden should credit the announcement that she...had been chosen to be the mother of God."
Come, Thou Long-Expected Jesus, p. 26.