Is the Virgin Birth Essential?

I suppose it depends on what you mean by essential. In one sense it's not essential to the deity of Jesus Christ. We shouldn't think that it was in virtue of his being virginally conceived that Jesus was divine. Even if he had had a human father, he still would have had a divine nature which he possessed from eternity past before he assumed a human nature as well. Nor is the virgin birth essential to the sinlessness of Jesus. If you think that original sin is passed on by human procreation, well then he would inherit original sin from Mary alone without Joseph. So Roman Catholics have been compelled to affirm that Mary herself was immaculately conceived without original sin, a doctrine which has no biblical basis at all. So I would say that the virgin birth is essential only in the sense that the Bible affirms it, that both Matthew and Luke teach it. It's clearly meant to be taken as the way in which Jesus was conceived. It may be that Jesus is to be understood as the Son of God in virtue of his virginal conception. Luke says that the angel tells Mary, “Because the Holy Spirit is going to come upon you, that which is born of you will be called the Son of God.” So the virginal conception is inherent to the biblical view of Jesus, but it's not essential to his deity or sinlessness in the way that some may have thought.