Christians regulary affirm that Jesus was "conceived by the Holy Spirit, born of the Virgin Mary." This faith is embedded as a cornerstone of all the major Christian creeds and is central to the Christmas story, read and re-told countless times at this season in both word and song. Surprisingly, the gospel of Mark has no account of the birth of Jesus. It opens with Jesus as an adult, traveling from Nazareth down to the Jordan River to be baptized by John. Since Mark is our earliest gospel the question arises--what is the origin of the idea of Jesus' virgin birth? When and where did it originate?
In contrast to Mark both Matthew and Luke give us different versions of the "Christmas story," but they both agree on the source of Mary's pregnancy. In Matthew's account Joseph had a dream shortly after finding out about the pregnancy. In this dream an angel told him that her pregnancy was "by a holy spirit" and that he was to go ahead with the marriage regardless. He was to name her child Jesus. By marrying a pregnant woman who carried a child that was not his, and legally naming that child, he was in effect "adopting" Jesus as his legal son. The phrase "by a holy spirit" implies that the pregnancy came from the agency of God's spirit but falls short of saying, outright, that God was the father of Jesus in the sense that, say, Zeus was said to be the father of Hercules by his seduction of his mother, Alkmene. In that sense the account is different from those miraculous birth stories so common in Greco-Roman mythology.