Christian teaching regards homosexuality as a sin and IMO that is a lie of weakness and opportunistic convenience to justify fear and loathing of the sex curse (added by God for us to wallow in and find pleasure in filth as punishment after being made mortal and kicked out of the Garden of Eden for original sin according to their contradicted view) of strong natural urges.
I'm backpedaling but you are now saying it is your opinion?!
Dissembling and attributing false motives only shows that you have a low opinion of people of faith and certain views on homosexuality.
Tell, me how can you conclusively know that homosexuality is not a sin? Put more broadly, how can you conclusively know what actions, thoughts, etc are a sin? Without that answer, you are mistaking a difference of opinion for a difference of fact.
While I don't feel like rehashing the whole homosexuality issue (it has been done to death on this forum already) it is hardly an indefensible position to view homosexuality as unnatural and sinful. If it were truly genetic, it would be an evolutionary dead end. Also considering the track record of marriage in countries with gay marriage concerning things like illegitimacy rates, views on marriage, etc. it is not hard to see that it works against the natural order. Add in the basic premise of God creating that natural order and it is easy to reach the conclusion that homosexuality is sinful, scripture and personal "fear and loathing" aside.
It seems more than a little opportunistic to insinuate that a position you oppose (or don't understand) is mere opinion based on dogma while a position you agree with (and may also not fully understand) is self-evident truth. Kinda hard to have any productive dialog when you are approaching it from that viewpoint, don't you think?