Homosexual people should have all the same rights that everyone else has for quite a few reasons. It is true that people who are homosexual have a trait that makes them different from the majority of people, but that does not mean they don't deserve the same rights.
There is nothing wrong with being attracted to people of the same gender. It just means you have a trait that is different from the majority of people, but there is nothing wrong with that. Someone who is handicapped is different from the majority of people, but he or she still gets the same right as everyone else. So why shouldn't homosexuals get the same rights as well?
Homosexuality does nothing to hurt us in any way. If anything, it helps society, because gay people cannot reproduce with each other without the assistance of technology. Therefore, they are not adding to the population burden the world is currently facing. If they are not doing anything to hurt people, they deserve all the same rights that everyone else does.
People argue that gay people shouldn't be allowed to marry because that is not abiding by what God told us to do. Even if that is true, there is still the separation of church and state. Legal recognition of marriage is a civil agreement, not a religious one. There is absolutely no reason that homosexual people should be punished or have different rights from other people.