Please forgive me for this assumption if I am wrong, but I would assume that you are homosexual yourself("I myself think that we should all be treated equally"), correct?
I just find it strange that you use the term 'gay' to describe homosexual-ism(is this a word anyways, the 'ism' part of it?). I've ended up in a debate just for using the term 'gay' to describe something(basically like, "that's gay"). Not to stir up anything on that, but frankly gay doesn't mean homosexual, and I don't really like when people take it that way, or take it to offense. If someone calls something gay, they surely don't mean 'homosexual' and aren't trying to be offensive(probably most of the time). Now if someone calls a person gay, that is different.
But back to the subject, I honestly don't care that much. Just meaning homosexual people are still people, just like heterosexual people. While it may seem unordinary or unatural to be attracted to the same gender, in todays world what does it really matter.
While many people will argue with religion, I say to you, just think clearly about it all for a second. While many figures in the bible were not homosexual, and there is never really a direct mention of anyone being so, and then you have the fact that God created a man, then for this man he created a woman, as a life partner really. So most people think it is a deadly sin to be homosexual. But try to remember God gave us 10 commandments. These are things that should never be done. If you believe in God then you should know these commandments are taboo. But not one of them says, "Thou shalt not love thy own gender." People break those commandments all the time, so even if being homosexual was wrong, that is the least of the sin in the world today.
It is hard to say whether or not you can be born homosexual or not. With all the crazy science of today(the genome project, etc.) it is hard to really know if there is something the causes someone to be homosexual. There are people who are not born homosexual and later on choose to be so, but there are still some cases that make you wonder. Just as there can be a number of stange birth irregularities(for instance someone who was born with both sexual organs), it would seem that it could be possible that someone could be born and their natual instinct is affection for their own gender, rathar than the majority populations affection for the oppisite. I guess someone would really have to understand the mind completely and such to prove either one.
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To clarify my post here, I am not attempting to bash homosexuals in any way. I also am not homosexual, and personally would never care to be, but this doesn't mean I hate homosexuals or their lifestyle.
If people can live their lives doing so many other things(mostly illegal or immoral), then what does it really matter if people choose to live their lives loving the same gender? If you consider homosexuality to be something bad, then compare it to other crimes/sins and then it probably won't look as bad.