I'm an agnostic. I find it illogical to believe in a deity when there is no evidence... but most logical arguments behind complete atheism are based on a priori reasoning, which I am loath to use in this context. Either way, I'm not even sure whether or not I want there to be a god (although I probably want there to be an afterlife, even if I don't believe in one). One thing for sure is that I believe that no religion that I know of is true if their beliefs and texts are taken literally. Another thing is that I place scientific and other empirically and logically grounded knowledge above religious beliefs.
However, I can see why people want to believe in a god, and I don't think that believing in a god makes a person stupid or gullible (but maybe less-than-perfectly-empirical). I think that some high-profile atheists, like Richard Dawkins and James Randi, are sort of jerks, although there are plenty of jerks on the other side, too. What annoys me is when religious people try to mix religion with logic or science, like when foolish fundamentalists try to get creationism taught alongside evolution. It's like saying that churches have to teach the virtues of Paganism at Sunday school.