Kids get it much more easily than adults, I think. They don't generally think of love as being sexual, or dirty in any way. The thought of that simply isn't there. So it isn't hard to grasp that just as a little boy innocently and unconditionally loves his father, two men may love each other. In the eyes of god, alah, budda, or whoever, love is love, and that in itself is precious.
People who are gay or bisexual are, for the most part, born this way. They can't help the way they are, and thus their dislike of other people trying to change them. I could go into the entire dialectic of the scientific reasons of why this is true, but I doubt you really need all that, and if you do, there are plenty of places to look it up. Simply put - just as I was born a straight woman, the boy sitting next to me in class may have been born a gay male. It isn't something that they can change, and it is not by any means a bad thing, at all.
The only bad thing would be if people were incapable of love altogether! I can't even imagine that.
Now, transgender people have it very rough. Imagine feeling like a woman, but being in a man's body. Many transgender people even love women, though they are male, and still want to become a woman themselves. This is a compulsion they can't help, and since we have the technology to make their lives whole, why not do it? Everyone deserves happiness, and to feel like they are truly the person that they were meant to be.