I think the interesting part here is that some people choose to want some sort of proof for everything, not just whether god exists, but it holds true in every other scenario as well, such as the million dollars or flag on the moon scenario, we believe (or mostly believe) when we see some sort of evidence that supports it, not just because there is a lack of evidence to disprove it. There are any number of things that cannot actually be disproved, spiderman, the hulk, thor, the loch ness monster, bigfoot, aliens, santa clause, the tooth fairy, the gods of olympus, other religions beliefs for that matter. And most people tend not to believe in those things. Why is it that some people choose to make an exception to one claim in particular, even though when fully considered, the claim is no less far fetched than many of the other ones...? People will completely disregard other religions beliefs as false, even though they can't be disproved either but still stand steadfast to the belief that theirs exists and is correct. It is this kind of contradictory behavior that non-religious people cannot grasp. How can you be so certain that your religion exists and is correct, when you completely disregard or disbelieve other things that meet the same criteria you use to choose to believe in something...?