God only knows. Hahahaha. They've convinced themselves that it is unnatural and against God's "orders." Actually, it is as natural as heterosexuality, but they won't admit that. The Bible is more important than humanity. Just listen to wackdoodles like Kent Hovind and his creationist ilk. Facts go through their heads like light beams and keep on amoving.

Gay and transgender people don't fit neatly into your typical religion's breeding programme, therefore they're not welcome. Though the Catholic Church has found a use for its homosexuals (girls to the convent, boys to the seminary - dress them in black and put them in charge of PR) it still lives in a state of denial about it. It hasn't figured out how to deal with transgender* people yet.

*Please folks, it's an adjective, not a noun** (though 'transsexual' is both, which I think is the source of the confusion.) "They are transgender." - fine. "They are a transgender individual" - also fine. "They are a transgender." - it's like saying "They are a tall."

**Yes, I know some dictionaries say it can be either. They're wrong.

Because their holy books say we're sinful, an abomination, etc. and their holy books can't possibly be wrong ( of course ). It's easier to just believe than to actually look into these things objectively.

Because they want, desire and NEED complete control over the people believing and trusting in them. After all, there are lots of other churches, denominations and others out there bleating the same message. Its all about control and the money. This actually applies to any structured system be it religious, habit-forming or dare I say the latest new diet?

Most of the leaders and the majority of their followers are wholly ignorant of facts about evolution and genetics. Every system needs a fall guy to work.

Because historically religions controlled heterosexuality and the people attached. Homosexuals went around the control mechanism (demonisation of unwed mothers) putting them partially out of the power of the priests and that could not be allowed (possibly for very good reasons of tribal survival when first written). So they used a simple but effective means to bring those people (chiefly men, women were mostly property) back under control.

Easy..it's the only "sin" they can condemn that they don't do themselves...from being born heterosexual.

1. Because they're assholes.
2. They think their space wizard is against LGBT
3. People fear what they don't understand, thus breeds hate.
4. They tend to believe what's in their little books to be factual. Despite being translated many, many different times over and over. Whereas the original scripts are locked away. (Sounds pretty fucking suspicious to me)

Side note: Wouldn't it be fucking funny that if we are all wrong and there IS a god. And God happens to be the biggest, flamboyant guy man in existence? Those Bible thumper would be shell shocked.

Because lack of and/or compassion. For someone to think that it is an easy life picking any of those choices, is crazy. I think we should just accept people like they are as long as they aren't hurting other people, Who cares what goes on in their homes, in their bedrooms? Republicans are for keeping government out of our homes, stay out of it bedrooms first!

Simple, jealousy. We don't lead our lives by a book of fables..

For the same reason that it abhors masturbation, and Catholicism still has a bee in its bonnet about contraception.

Religion is a breeding programme. God owns your genitals, and decrees that the only time you should get any pleasure from them is when you're trying to make babies for him. That takes a fertile male and a fertile female. Two males doesn't work. Two females doesn't work. People who surgically transition render themselves infertile in the process. There's an acceptance of straight couples with fertilitiy issues: God's decision rather than theirs to make them infertile, and he could provide them with a miracle, after all. But even a deity that can create a whole universe can't make a man pregnant, make a woman pregnant from another woman, or create an opportunity for fertility in someone who's had their testicles removed as part of reassignment surgery.

Catholicism takes its gay men and women, dresses them in black and puts them in charge of PR. Girls to the convent, boys to the seminary. I've watched it happen to the grandson of one of my mum's friends less than a decade ago: caught with gay porn on his computer, his Internet rights are revoked by his parents, and 6 months later, he's enrolled in the clergy.

Catholicism hasn't worked out what to do with it's transgender people yet, which is why it still hates them so much.

It's the one "sin" the religious people (probably) haven't done, so feel safe to loudly condemn.
However, a Harvard study showed that ALL homophobic males tested showed sexual arousal when shown male gay porn.

Harvard study reveals that all homophobic people are gay [youreadygrandma.com]