Matthew might want to take a look at:
"The virgin birth of Jesus: Fact or fable?"
at:
http://www.religioustolerance.org/virgin_b.htm
Particularly the section entitled:
"Beliefs of Liberal Christian Theologians and Faith Groups"
Matthew needs to have ready rebuttals for all the points raised in that section.
¡Salud!
Mike, aka Elfish Chimera