If Jesus were a mythological figure, his parentage might make him a kind of demigod: A human-divine hybrid, a superman, fallible and yet with abilities beyond the rest of us. The incarnation we celebrate at Christmas is so much more than that.
It seems enough to say that through Christmas we have Good Friday and Easter. But Jesus’ coming to Earth was not just a relocation to shorten the commute to the cross. Distance is nothing to God. He could have dispensed with the messy business of teaching, healing and discipling, and just made His triumphal entry vertically.
That would have been a good show, but it wouldn’t have completed the humanly impossible math God was working out. One God plus one human did not produce half a god and half a man, or some dual or divided being. Jesus was all God because God alone was holy enough and perfect enough to be an acceptable sacrifice for humanity’s sins. He was all man because he had to identify fully with those he would redeem, from the womb through helpless infancy to all the struggles and temptations of earthly life.
No spinner of myths could conjure the miracle that is Christmas. One plus one equaled one savior, all God and all man, as it had to be.