The virgin birth is an explanation, not a proof. The fact that it is incredible, if it were not true, why would anyone include it in the story about Jesus? Of what benefit to the narrative does it provide except to complicate the matter for modern enlightened minds like those of this generation? This, I believe, becomes one of the strongest arguments in favor of it having occurred. It doesn't help skeptics believe and in fact dissuades them from doing so.
May I suggest that God doesn't seek to convince us of anything. He is completely comfortable presenting himself through the events and writings of men and women over approximately one-thousand-five-hundred years, who, when their thoughts and experiences are combined together, speak and demonstrate in a remarkably clear way, that God not only exists, but is in complete control.
If God can create the universe out of nothing, which includes forming you and me in our time, what is so difficult about a virgin birth?
It is true, at first, that whether the virgin birth was real, was not of any importance to you or me when we were first seriously thinking about giving our lives to God. In fact, our beginnings as believers in God and no longer scoffers (assuming of course this describes you) was not really about God at all. It was about our problem with the fact that our lives would eventually end, and there was nothing we could do in our own strength and intelligence about it.
This moment of clarity might come at the deathbed of a loved one, or following an accident, or a bad dream, but reduces easily down to a single simple question, “Have I reached the end of my rope?”
…yet you do not know what tomorrow will bring. What is your life? For you are a mist that appears for a little time and then vanishes.
James 4:14 (ESV)
This begins our search that hopefully ends in discovering a God who, among many amazing things, loves us so much that he chose to become flesh and dwell among us. He chose to join his DNA with a young virgin to become the baby we all desperately needed to come.
Much later, in my case, I eventually began to discover that the virgin birth is indeed essential to helping my faith continue to strengthen and grow toward the heart of the amazing God I serve.