Religion in RPGs

This is just a quick post, as the subject came to mind while working out things for Carolis.

Carolis was conceived as a world without gods and clerics since, well, it makes the setting more dangerous. And because I had used gods in most every other setting and wanted to try somethng new. That doesn't mean there aren't religions (the druids have a pretty involved one, tho it's private), just that there are not, strictly speaking, any gods (druids, somewhat accepted). Most religions tend to be the mystery cult variety, and have little to not political impact in the "real" world on a large scale.
On a private scale, they're rather powerful, much like the masons. You give favours to friends in the same religion, etc. One reason for this is the same reason there are no guilds: the power of religioins is their appeal to ideals and emotions, and makes them hard to control for the political powers (the guilds are more because they could be an economic throeat).

But as for RPGs in general, I'm not sure how well gods work, especially if gods aren't met on a daily basis and the like. I mean, religion was a BIG part of people's lives in the middle ages, and in most games set in the same millieu it would stand to reason that it's as big. But it seldom is. Some of this is because most GMs don't really make a viable, "real" religions, others is because players tend to operate on the modern assumption that "It's all fake, and exists for the power of those on the top". Which may or may not be true. In any event, getting pcs to really *believe* seems difficult because of this, especially if the gods are never actually present.

Any other thoughts or ideas on the subject?