Religion
The members of my immediate group at work have known for a while that I don't drink alcohol, don't usually consume caffeine (except in chocolate), and don't smoke. (And don't eat red meat.) They've also seen the aging Habitat for Humanity bumper sticker on my car. And they know that I used to fly out to Salt Lake City now and then. And a couple weeks ago, very nervously, I mentioned in passing to them (in an email about an outside-of-work dinner party the group was having) that Kam was "one of my sweeties."
I wonder if any of them have connected the dots and erroneously concluded that I'm a Mormon.
I'm fascinated by religion. I'm an agnostic myself, with occasional atheist leanings and occasional leanings toward mysticism of various sorts, but I have a lot of religious friends, and it's clear to me that religion is a huge part of a lot of people's lives. I sort of feel like if I want to really understand people (which I tend to feel is an important goal for a writer), knowing about religion is essential. Arguably, an intellectual knowledge of religion isn't enough; I would guess that to truly understand faith, you have to have it. But since I don't (well, okay, I have a fair bit of faith in the scientific/rationalist worldview, but although that's related, I don't think it's quite the same thing), intellectual knowledge about religion is probably as close as I'm likely to get.
The dislike of religion that I see in the speculative fiction community bothers me. The fannish community prides itself on being accepting of differences, but it seems to me that devout adherence to any religion other than perhaps paganism tends to be viewed in fandom with distaste bordering on distrust. This is understandable; many people in the sf world have received unpleasant treatment from religious people, and many others pride themselves on a scientific/rational worldview that they feel leaves no room for "superstition." (Though there are many scientists who are also religious.) But it's divisive, and it bothers me—and I see it in the fiction as well. Too many science fiction stories either slam organized religion or simply ignore it (besides being straight and monogamous, the vast interstellar society of the future is monolithically and devoutly secular humanist). (And when they slam religion, it's often by setting up a straw-man religious character whose weak arguments the smart scientifical characters can easily demolish. Hint: if you're going to feature a religious argument in your book, go read some of the great religious thinkers and see whether your argument is an old one. It probably is.) Too many fantasy stories feature the good guys (the magic-using people, often allied with the world of Faerie one way or another) battling the evil and intolerant Church.
That last in particular (good guys vs. intolerant Church) is a tempting story to tell, 'cause everyone likes an underdog, and everyone can see the intolerance that some kinds of religious people have in the real world, and it's emotionally compelling. But it's a cliche (it's been done many many times), and it relies on a stereotype. If the only religious people in a story are fanatical Spanish Inquisition types, eyes gleaming, ready to burn all witches and heretics, that's just as much a stereotype as having flouncy gay guys in your story, or watermelon-eating poor ignorant Southern black guys, or Chinese-Americans who are quiet and well-mannered and do well in school, or whatever.
Huh. This seems to have turned into a rant. I didn't really mean it to; sorry. I should note that there are lots of good speculative fiction stories in which religion plays an important or even central role, and/or which feature prominent religious characters who aren't evil or insane. (There's a good page about religion in sf, featuring 34,000 citations, but I suspect there are plenty of works not listed there.) Religion is a great way to examine fundamental questions about humanity and the universe, and plenty of authors have taken advantage of that fact. And some science fiction probably even romanticizes various religions; I note in particular that there seem to be a fair number of stories and books featuring interesting Jesuit characters, and I am not at all immune to the allure of the (stereotypical?) fictional Jesuit—brilliant, perhaps slightly eccentric, inquiring after Knowledge at any cost.
In conclusion, I'm not sure I have a conclusion. Except: religion has been a part of the human experience and has helped shape human society for thousands of years, and if you're gonna write about humans, I think it's a good idea to take that into account. 'Nuff said.