Why are we not then, all of us going over to the a birthers forum and combating that?
Because we're here. I was using Birthers as an example. What these theists are doing is the same as if you asked a Birther for proof of their claims and then they said, "You prove that we're wrong."
When someone makes an extraordinary claim, it shouldn't be verboten to ask them to back it up with some evidence.
Saying that there is a being outside of the space time continuum that is all powerful and that he created the universe in which we live and everything in it is an even more extraordinary claim than what the birthers are asserting.
Why do people get so upset when you ask them for proof of that claim?