Homosexuality has no genetic root. There is no "homosexual gene".
To be fair, there's not really a heterosexual gene either.
Not that I'm aware of anyway.
Being homosexual is the result of personal experience and how it shapes the personality of a person, already at a very young age.
Somehow, it's our society that produces homosexuals. Our culture is the source of homosexuality.
LOL! Yeah, cause people like Oscar Wilde or Alan Turing who lived in a society which explicitly outlawed homosexuality (and FYI both were severely punished by said society for homosexual acts) were totally that way because of society.
Not to mention that heterosexuality is lauded in today's society, not as severe as making homosexuality illegal, at least not in the West. But today's society is merely gay friendly-ish, not be gay all day. Not the same thing, mate.
Also if that is the case, are heterosexuals that way because society to this day goes out of its way to say that being straight is better? Or by your own arguments did so in the past? Rather severely.
You must have a very fluid sexuality if you think something like that is shaped by society. Not that there's anything wrong with that, of course.
Claiming that it's a sin to be homosexual is unfair because those who are homosexual have been forced into it. They didn't chose. Society shaped them into it.
You must live in a veritable Mardi Gras all day every day where you live. Which society do you speak of? Because I have only observed being "okay with being gay" in my society. Mostly. Again, not the same thing as enforcing homosexuality on people.
So unless we see a reason of seeing homosexuality as a threat to humanity, there is no reason to reject it, but just accept it as one of the possibilities that humanity has within it's specie.
Well that I can agree with wholeheartedly.