The second miracle of Christmas announced to Mary by the angel Gabriel is the Virgin Birth. Strangely, this miracle was not a problem for the ancients. At least no strong opposition to its being possible has been recorded. It is only in recent times, in the earlier decades of this century, that the Virgin Birth has been discounted. It was attacked by the unbelieving liberal element in Christianity.
God always has his champions, of course. And in this case his champion was a New Testament scholar by the name of J. Gresham Machen. Machen examined the matter as only a scholar of his outstanding stature could. He showed that the idea of the Virgin Birth was not something added to Christianity at some later time through error, deceit, or superstition. Rather, it was present in Christianity from the earliest possible moment, it is preserved in the earliest portions of the New Testament sources, and it is probably to be traced to the earliest possible witness to the Virgin Birth, namely, Mary herself. So exhaustive and brilliant was Machen’s book that no one, not even the most articulate or militant of the liberal scholars, answered it.3 They could not, because the doctrine is true and Machen’s points were unassailable.
True, we do not know how God could cause a virgin to conceive and so bear his Son. The conception is clearly a miracle. But that God did so is no less clearly a fact of human history. Is the fact important?
How could it not be? The Virgin Birth is important because it proves that Jesus Christ is the only begotten Son of God. He has a divine as well as a fully human nature. It is important because it fixes the moment of the incarnation at the conception of Jesus rather that at some later point as some liberal theologies would have it. And it enforces the utter sinlessness of the Savior. Jesus needed to be sinless if he were to accomplish the mission for which the Father sent him into the world. Only the Holy One of God could make an acceptable atonement for our sin.
3J. Gresham Machen, The Virgin Birth of Christ (London: James Clarke & Co., 1958).