Late to the game, but I'm precisely in this boat.

I don't have faith -- if I did, I'd have no qualms whatsoever about facts and arguments presented by atheists. I wouldn't be nervously claiming that the dragon is invisible. (Some people who think the apocalypse is nigh actually do stockpile canned food. That's faith; they believe in Revelations the same way I believe in physics.) I don't have faith, because I'm actually frightened that some archaeologist will find evidence that there wasn't any Exodus, for instance. And the fear is really that changing my religious beliefs will make me a worse person. Less grateful? Less reverent? Less respectful? That's the basic idea but I'm not sure if those words convey it.

To give a non-religious analogy, take the question of whether men have evolved to be irresponsible fathers. That's an empirical question. But a man can be afraid of believing that he is, indeed, biologically designed to be an irresponsible father, because he fears that such a belief will make him actually treat his children poorly. A rational man, we'd hope, would decide "I'll be a good father, whatever the evolutionary biologists say." But he can only do that if he has some independent reason to be a good father, and if he's aware he does.

A religious person wants to be a good person, and wants to have the right sort of attitude to the world. But all his reasons and motivations come from God. He could fear not believing in God because he fears not being good. Presumably, he has some other, non-God motivations for wanting to be good; but let's say that he doesn't know what they are. Then his fear might be justified. With no God and no principles, his behavior might actually change.