What I mean is, what reasons would make you refuse to believe, and how belief in God is a bad thing in general for you.
I like the ideas mentioned before that if an SJ has been raised with atheistic ideals he will believe on in that manner, or the idea of being a scientist (modern science is strongly influenced by atheistic philosophies).
I am a Christian myself, by the way.
Just curious to hear what you SJs would have to say about it. This is about a novel I am working on. The character's aunt (and tutor) is a SJ atheist and dislikes her niece being very spiritual because she sees it as error and thinks she will hurt herself. Does that make sense? The character (aunt) has been raised an atheist and her brother is an intellectual who provides ideas and reasons to reject the belief in God.
So as for my vision of the world:
I think you word it a little weird when you say "refuse to believe". It's more like I see no reason to believe. Basically, if I said that I believed in fairies you'd call me crazy. There is no evidence that fairies exist. And while I can't rule out the possibility of a God (or fairies), until some concrete evidence appears I see no reason to believe.
And while I'd hate to generalize, I find that by the nature of being religious people, many religious people are somewhat ignorant (or possibly just blind). Believers will tell stories of how they know God is real. I used to do this myself. I would explain to people that whenever I didn't do my homework (which was rare) the teachers would never check, and thus God exists; but this totally ignores the fact that it could be just plain coincidence. (I'm sure I wouldn't have made that mistake if people had told me stories of all the times they didn't do their homework and got caught.) I don't think being religious though can really hurt somebody most of the time; more like the person is signing up for slavery. It's just foolish, limiting, and blinding. To believer in my eyes, suggest a certain amount of gullibility on the part of the believer. And while I say that religion most of the time won't hurt, 9/11 is proof that religion certainly can be bad.
And somewhat recently, I explained to my parents that I longer believed in God which was a lot of fun. I was able to argue and reveal how little they know about their own faith and only confirm my assumptions that believers are just blind. My mom even sent me to talk with the local pastor. We talked for a few hours and again, I only saw how blind people can be. I think that's only natural though, that is, to not renounce one's faith. People treat ideas like possessions.
I also very much dislike the people who believe that atheists can't have morals. Morality is a social thing; not a religious one. If everybody believed it was okay to kill others then it would be. There is so much evidence for this.
If it's of any interest to you, I used to be a Catholic myself. Being an SJ perfectionist though, I wanted to understand my thinking so that I might do better, leading me to the MBTI, critical thinking, and the realization that I had no reason to believe in God.