Any discussion with an orthodox/fundamentalist Christian about the validity of Christianity will at some point involve a review of the “overwhelming evidence” for the existence of a Creator God. “Something cannot evolve from nothing”, conservative Christians are famous for saying.
However, this argument is only valid if one is debating someone who denies the existence of a Creator god—an atheist. I, for example, have no problem with accepting the possibility that a supernatural being created the Universe. So the fundamental issue upon which to begin a debate with an agnostic like myself is this:
If there is a Creator, exactly who is he, or she, or it? Can conservative Christians provide convincing evidence that the Creator of the Universe is the Hebrew god, Yahweh, who Christians believe is one and the same as their god—God the Father, Son, and Holy Ghost?