There's a fundamental error of conception that is frequently made by religionists. This error is to assume that atheists are "denying" something. In fact, atheists are simply rational human beings applying a rational rule. As Truzzi said, "extraordinary claims require extraordinary evidence." There is no shortage of nonsense people can choose to believe; it would be absurd to expect intelligent people to spend their lives refuting nonsense. Instead, the onus is entirely on those who make a claim to support it with tangible repeatable evidence. If they can't do that, then they merely have a belief, and beliefs are ten-a-penny and in fact worthless. Atheists are simply people who don't naively believe whatever they're told but instead wait for proof. In the absence of proof, there's nothing worth considering. People who shout "you can't disprove my god exists" are merely silly and unworthy of attention because they have failed to grasp the most basic aspects of reasoning.