Affirming or confessing the virginal conception of Jesus is part of the Creed, so the virginal conception figures as a line in Christian orthodoxy. But how important is it? Can one deny it and be a Christian? (One can’t deny it and be fully orthodox, if one defines orthodoxy by the Creed.) Mike Bird, in Evangelical Theology, sketches the doctrine of the birth of Jesus and the virginal conception of Jesus in the womb of Mary.
1. It is explicit in Matthew 1:18-25 and Luke 1:27, 34-35. It is only possibly found elsewhere, and Bird suggests Galatians 4:4 and Mark 6:3 and John 8:41. Thus, it is apostolic but not found in all the apostles. (I’ve never understood why the absence of this idea in Paul means Paul didn’t believe it, and Bird says it is not a part of the core of the gospel but part of the gospel — p. 370.)
2. The virginal conception is not predicted in Isaiah 7:14 where there is a prediction that a young woman would conceive. Matthew uses the LXX translation to confirm prophesy of what he knew happened (the virginal conception). But there is very little indication of Matthean or Lukan dependency on any kind of ancient pagan divine-human intercourse. The NT narratives are saturated with OT allusion and quotation.
3. So why the virginal conception? (I have discussion of this in my book The Real Mary, if you care to see more treatment.) Bird agrees with Mark Strauss to say the NT does not explain it or develop its significance; it remains mysterious. The issue is not the DNA of a male, who passes on sin, removed from Jesus so he could be sinless since DNA is passed on by both parents. Bird suggests we approach this from the angle of why it has been denied.
The virginal conception means Jesus was not simply a holy man and not a cosmic ghost (his terms). Jesus is the one special son of Israel. Furthermore, this doctrine speaks to new creation coming into existence in the here and now as a foretaste of what is to come. And it speaks of the overcoming of evil and injustice and the conquering of satan. Thus, Rev 12 has the dragon wanting to slay the child because the dragon knows what the child will accomplish. The virginal conception affirms humanity, affirms the path of normal childbearing and birth.
Bird says he’d not put this in “my top five doctrines” (374). It’s chief significance then is to be found “in its christological meaning that the Word was made flesh in one of the most bodily events of human existence, namely, childbirth” (374). It teaches incarnation instead of “transmutation of the Word into human form.” God becomes human to rescue humans from themselves and the clutches of the evil one and evil injustices. As Barth put it, “the Virgin birth is part of real Christian faith” (375).