One problem is that every race has a "feeling" on something. Klyros is a popular race, and so are Diaboli, along with any others that, in the settings history itself, don't believe in any of the Gods. So you're calling them lazy?
Now, in real life, I call myself a Christian, but I never go to church or anything of the sort. I simply believe, that's all. Does that make me an atheist? Probably, but that doesn't mean religions in here necessarily have to have you praise and worship them to believe in them. Feelings like this develop, and until a miracle happens that may make them believe further, there's really no point in them believing in the religion to begin with.