In 1924, more than a thousand Presbyterian ministers endorsed a document that is called the Auburn Affirmation.1 This affirmation was a protest against the actions of the 1923 General Assembly, which they claimed erroneously elevated five key doctrines of Christianity to the status of tests of orthodoxy. Among those five key doctrines was the virgin birth of Christ, which is expressed in the Apostles’ Creed with these words: “who was conceived by the Holy Spirit and born of the Virgin Mary.”
Despite the well-articulated presentation of this protest against the actions of the 1923 General Assembly, its attempt to preserve liberty of conscience over against key doctrines of Christianity in the end put the signers of this affirmation on the road to denying the gospel. Gordon Clark helpfully pointed out the danger of describing the virgin birth of Christ as a “theory” as the Auburn Affirmation did:
Now to be concrete, what "theory" other than the historical fact of the virgin birth, can you think of to explain the incarnation? There is one which the anti-christian Celsus used in his effort to defame Christ. If Christ be not virgin-born, and if, as both Joseph and Mary claim, Joseph was not Jesus' father, whose son is he? Does the Auburn Affirmation really mean that one who accepts this view of our Lord's birth is worthy of all confidence and fellowship? That is exactly what the Auburn Affirmation means. It says definitely that ministers are worthy of confidence "whatever theories they may employ to explain" the incarnation.2
Now, this critique does raise the question of why it is so important to affirm the virgin birth of Christ. Why is this a key doctrine of the faith? Joel Beeke offers some helpful thoughts:
When we consider the alternatives, as Grudem points out, we can see that the virgin birth was a very wise means by which to signal the entrance of the incarnate Son into the world. If God had created the human nature of Jesus without him being conceived and born of a human mother, then it would be more difficult for us to believe that Christ is truly human. If God had brought forth Jesus by the ordinary union of a man and woman, then it would be more difficult for us to believe that Christ is truly God—he would seem merely human. However, Jesus’s virgin birth from a human mother illustrates both his deity and his humanity.3
To add to that, the virgin birth points us to the inauguration of the new creation. The active work of the Holy Spirit in the birth of the Lord Jesus reflects the work of the Spirit in the original creation as “the Spirit of God was hovering over the face of the waters” (Gen 1:2 ESV). The birth of Christ was the intrusion of something new and “very good” into the old and corrupt creation. This simply reinforces how the Lord Jesus Christ is the unique mediator of salvation, for he comes from without, enters in, and brings redemption and renewal in a way that no mere man could do.
In the end, the virgin birth is a matter of faith, which is one reason that some of those who signed the Auburn Affirmation had a hard time with it. It forces us to trust in God rather than ourselves, which is, of course, part and parcel of God’s plan of redemption. Joel Beeke puts it this way:
The virgin birth calls us to submit our minds and hearts to God's Word, regardless of how difficult it may be to accept. Mary and Joseph are our examples in this matter, for despite the potential scandal of her pregnancy, they believed God’s word and submitted to his will (Matt 1:24-25; Luke 1:38). In the same way, we must trust in the supernatural power and faithfulness of the God who revealed his Son in this manner. If God cannot be trusted with this, then how can we trust him to save us from hell and raise us from the dead to reign with Christ forever?4
3Joel R. Beeke and Paul M. Smalley, Reformed Systematic Theology (Wheaton, Illinois: Crossway, 2019), 2:794.
4Beeke and Smalley, Reformed Systematic Theology, 2:794.