And you are a coward. Because in face of a homosexual, you avoid the implications of what you are saying. By answering "lust is a sin" to "is homosexuality evil" (and by the principle of implicit relevancy) you let your interlocutor infer "therefore homosexuality is evil" without saying to their face "you are evil".
Which you happen to be. Because fanatically fetishizing your inane dogmas at the expanse of human beings, at the expanse of curiosity and knowledge, prioritizing your symbols over actual lives, is (like violences on a flag's behalf, like punishing blasphemy, like crushing lives to satisfy bureaucratic categories) the most direct manifestation of dehumanization. It's disregard for reality and for people. In order to preserve some onanistic, circular system of belief which geopolitial functions (such as "grow and multiply in order to add power to our clan") have long lost their object. You're a wheel spinning in the void, incapable to understand its original purpose, for the sole remaining benefit of flattering your collective in-group out-group vanity.
It would be simply amusing if it was about physical objects. But the fact that there are actual human experiences at stake, the fact that your views toy with other people's real (and unique lives) make you an extremely bad person. But protected by a system of belief that requires to be locked as tightly as possible in order to prevent this realisation.
Fortunately, you are a minority. And the world's standards and mankind's self-awareness evolve despite of you. I'd rejoice about the distress it causes (or will cause) to you, if there wasn't something sad to pointless, ultimately self-inflicted distress. All it would take to lift it is, well, empathy, intelligence and good will.
But there are two kinds of harmfully ignorant people. Two kinds of "racists" (in the general sense of prejudices against human groups). There are good people, who, when presented with reasons to respect the object of their loathing, take it as good news. "Oh, I though these [homosexuals, jews, blacks, muslims, trans, natives, migrants, redhead, etc] were monsters, what a relief to realise I was disliking them wrongly and we are all the same on all the aspects that matter morally". And there are those who stay in denial, because this contempt is its own reward. Those for whom the rehumanization of others would be bad news. They need [homosexuals, jews, blacks, muslims, trans, natives, migrants, redhead, etc] to be monsters, because they need an object towards which to indulge in the feelings that monstrosity legtimizes. As if evil individuals didn't provide enough opportunites, they need human groups, recognisable through arbitrary collective traits (passports, color, language, religion, sexuality) in contrast to which to valorize their own (often just as imaginary) group.
This is the only real moral difference between humans. And it has nothing to do with sexuality, ethnicity, religion or phenotypes. It's a transversal difference, running through any human group. And that is why you being a bad person has nothing to do with you being a catholic, or any collective identities through which you -or others- define yourself. It has only to do with what you, as an individual, opt to make of these identities, and why.
This thread has been more informative about you as a person than about any human collectivity.