It is a fundamental property of the human psyche that you must want to believe in order to believe. Most things that you believe are things that you have accepted, rather than have been proven to you. A war goes on in another country and you accept this is actually happening because you believe the source to be credible. Conspiracy theorists don't want to believe, so they find reasons to not believe.
As I said though, reality doesn't really care what I believe. If I don't believe that there's a wall in front of me, well, reality will provide an abundance of contrary evidence if I try to run into it, or look through it. My belief won't influence reality, and in that respect, retaining such a belief, which contradicts the readily-available evidence, is either foolish, or a sign of psychological problems.
A leap of faith is absolutely necessary to believe anything. Only until you do believe something can "evidence" be found to justify the belief. The primary issue in these discussions is that people admit they don't care enough about the topic to put any effort into finding evidence, because they don't want to believe. Yet those same people put every bit of effort into telling everyone else they are wrong, and for no actual legitimate reason. It's a self-defense mechanism, justifying their own beliefs to avoid being challenged. It is completely transparent and obvious.
That's kind of delving into the philosophical realm, if I'm interpreting it right - as in, how do you know that your senses are giving you a reasonably accurate view of the world around you? If you want to get right down to it, you don't. And there's plenty of evidence to say that our senses don't give us the complete picture, and that they can easily be fooled. Yet there is still evidence of other things going on. If you enjoy playing with certain glowing rocks, you might eventually learn about the effects of radiation sickness. You can't see it, but there's evidence of its effects, so you build a tool to detect it. (Belief is still irrelevant here, the radiation sickness is quite evidently real.)
And I guess if you want me to say it, no, I wouldn't want most of humanity's deities to exist. A lot of them are petty, sadistic, chaotic, egocentric, uncompassionate, and childish. But belief isn't really the issue here. I also wouldn't want a crazed axe murderer to be sharing my apartment. Belief has no bearing on whether or not he's actually here. If I convince myself to believe he's not here when he actually is, reality (surprise beheading!) may say otherwise. If I convince myself to believe that he
is here when there's no sign of anyone else here,
then I might just be going a little bit nuts. (And yet believing in a horse that pulls the Sun along the sky....er, I mean, believing in
God, is considered by many to be perfectly rational.)