Yeah, and eating pork is a sin according to the Bible too. And we are obligated to stone gays. And we cant turn on a light on Saturdays. I can provve a lot using the Bible.
However, it has been slightly modified(if you are Christian, our bible has basically been forsaken). Plus, Rashi says "The Torah speaks the language of man", meaning that since we cant understand what God wants, it is put into language we can understand-ie the hand of God when God is not a corpreal being.
Anyways, we also have a commandment to "love thy neighbor as yourself". W shouldn't automatically say, when one follows their biological need to be gay, "he is a sinner and goes against God". One cannot help his sexual orientation. As I have said elsewhere in this forum, it is unhealthy to ignore this need. It is, in fact, being disrespectful of the body which God gave you. He chose to make you this way, give you this need.