Originally Posted by
alphabet55
I'm a Roman Catholic, and I can try to explain why Roman Catholics, at least, view the acts of homosexuality as sinful.
First, we believe that marriage is sacred. A man and a woman get married, and they make babies. Hooray. This was instituted by God (Adam and Eve, etc.), and Jesus said some things about marriage, too. I can't remember them verbatim, and I don't feel like looking them up, but I do know that they were specifically about heterosexual relationships. This is why premarital sex, etc. is bad. No marriage. Also, marriage should be entered into with the expectation that babies are a possibility. (No celibate marriages, lol.)
Second, in order for sex not to be sinful, there needs to be two things: pleasure and the possibility of creating life. Sex without pleasure (rape, etc.) is sinful, and sex without the possibility of creating life is sinful.
The latter is why Roman Catholics (or real ones, at least--not the name-only ones) believe that homosexuality (no pregnancy there), contraception (also no pregnancy), and other things like masturbation (duh) are sinful.
I don't expect this to convince anyone, but I figured that I could at least explain my understanding of why Roman Catholics see homosexual acts as wrong. If anyone has any questions, feel free to ask. ;)