The virgin birth always struck me as a strange "miracle". After all, if any woman said to you, I've never had sex, but I'm pregnant, would you suspect lying or miracle? How would anyone know she was a virgin? I think Martin Luther, of all people, had it right, the miracle was not that Mary had a virgin birth but that Joseph believed it.
If there is a god, I want to believe that there is a god. If there is not a god, I want to believe that there is no god.