For example, in my path in my study of Celtic- based (as opposed to Native American-based) shamanism, I've tried to research Shinto-ism, Taoism, Judaism, Christianity, Catholicism, Hinduism and naturalism. In doing so, I've learned more about my own faith, how it has inspired and been inspired by other faiths, and the common threads that such faiths have. Atheism, as well, helps me to study my own faith, for I find it helps to pause once in awhile and question that faith.
I think it's kind of like ice-cream. Sure, you might be certain that mint chocolate-chip is the best one out there and that it's the only kind for you, but if you've never even looked at the ingredients of the other flavors, your certainty lacks a logical basis. No one is asking you to 'taste' the other flavors, but it's nice to realize that the ingredients of mint chocolate- chip have a lot in common with those of other types of ice- cream!
Please refrain from the above metaphor if you're lactose intolerant. Thank you.