All right, I think I understand the problem, let me see if I can explain it to RK Joker in a better way:
On any subject, rational argument can only take you so far, at some point you will get down to some core VALUES you hold for which there is no rational basis. You might call these values "opinions" if you like. For example, I couldn't tell you why I like the color red better than yellow. The only argument you can give for why you hold your values is "I just do," they are not debatable.
Now RK, you said that you think homosexuality is a sin. When asked why, if you had just responded "I just do", then no one can argue against that, any more than they can argue against me liking red more than yellow. But that's not what you did.
You cited the Bible as a source for why you think that way: I think homosexuality is a sin because the Bible says so. Okay, but the Bible also says that it's a sin to eat shrimp and shellfish,
(Source) among other things why don't you believe those as well?
Now I already defended your right to choose what to believe out of your religion, but what you haven't explained is WHY you chose to believe this particular passage vs. any other passage. What exactly makes homosexuality different from eating shrimp? They're both prohibited in the Old Testament - furthermore, homosexuality is only implicitly prohibited while eating shrimp is explicitly prohibited.
If at this point you had said, "I accept the part of the Bible that states homosexuality is a sin because it is consistent with how I feel", in other words, "I just do", then again, no one can argue with that. But if that's the case, then you need to realize that the Bible is no longer a valid justification of your beliefs (at least when it comes to homosexuality), it is merely a convenient excuse to reinforce them.
You believe that homosexuality is wrong not because the Bible says so, but because you just feel it in your gut at some primal level, and the Bible happens to agree with it. You know what? That's FINE, because no one can tell you how to feel about something, any more than they can tell me how to feel about red vs. yellow. But you ought to acknowledge that's the case if you want the other posters off your back.