You realize that personal revelation is a perfectly acceptable reason for people to believe in god, right? Oly and Heph could just "think" there's a god because they think they can feel him or had experiences that lead them to believe he exists. That's acceptable as evidence for them, just not acceptable evidence for me or you. I'm not saying their feeling is correct, and I personally don't believe it is, but demanding they use their internal mental state as proof to you that god exists is trivial, and really juvenile.
Neither of them is willfully trying to change public policy based on their beliefs, so their beliefs don't need to be justified to anyone but themselves. And to my reccolection, neither of them has claimed that they actually have proof that god exists outside their own mental states. There's "evidence" in the bible to most believers, but I think Oly and Heph are both smart enough to realize that just because a book says something, doesn't make it so. It's more than just the bible telling believers to believe, something in their life has happened to make most believers feel close to god.
The only route that can be taken to try to debunk mental states is a deeper understanding of human psychology, why we believe the things we do, and why we have a hard time filtering our own thought patterns. It is my honest belief that religious people are simply misinterpreting their own brain signals, it's not a defect, or an illness. Even then it's just a best guess as there's so much we don't know about the brain.
It's funny really, most people assume they're an expert at their own mind because it's "theirs", when in reality most people don't have the foggiest clue as to how their own brain works or deals with stimuli.
(over the caterwaul, for sure)