Could you elaborate on your premise a bit?
I'm willing to give you the benefit of the doubt Tweed, but this sounds like an excuse to go "LOL Fundies!" based off a stereotype.
I wasn't quite going for that. the most prominent religions all seem to assert that sex outside of the context for man-woman marriage is inherently immoral. (despite their prominence in the West it's hard for me to imagine that any more than, say, 1 in 8 of followers of Abrahamic religions are "cool with" homosexual marriage.) some (ie, the RCC, the largest church in the world) even goes so far as to condemn sex for pleasure within marriage, as opposed to sex with the express goal of procreation.
this could all be quite reassuring to people who feel guilt, anxiety, fear, etc as regards their own sexuality: it validates the guilt. I've seen this process play out with a few people in my own life, which is why I brought it up.