We know that according to God's Word, if a man commits adultery in his heart, he is an adulator. The same applies to homosexuality. God tells us that of all the sins we commit, sexual immorality is the only one that is committed against the temple (body).
Let me give you an analogy:
Imagine that you are taking your small child to a day care center. You are greeted by a man who says he is going to be the primary cartaker for your child. He also says that he believes he was born with pedophile tendencies, but he does not act on them. He goes on to say that he has attraction for little kids, but will not act on it. Would you leave your child with him?
I agree that if a man commits homosexuality in his heart, he is a homosexual, just like if a man commits adultery in his heart he is an adulterer. But that is not what I'm talking about.
The man who commits adultery in his heart is not guilty just because he has a genetic attraction to women. He is guilty because he committed adultery in his heart. Likewise, the man who commits homosexuality in his heart is not guilty just because he has a "genetic" attraction to men. He is guilty because he has committed homosexuality in his heart.
Again, what is the Biblical definition of homosexuality? It seems to me that is is only lusting for somebody of the same gender or actually having sex with somebody of the same gender, but not merely having a genetic attraction to the same gender.
As for the pedophile analogy, if a man who knows he has pedophile tendencies and wants to be right with God and with the law, he must stay far away from children.
Likewise, a man who knows that he has a "natural" attraction for other men, yet wants to be right with the God of the Bible, first he has to repent and have faith in Jesus Christ, and then he must stay far away from other homosexual men. It's like a recovering alcoholic who wants to quit for good. He must stay away from his drinking buddies and from alcohol all together.
Please keep in mind that for the sake of our discussion, my questions and comments about this subject are made only assuming that homosexuality is genetic, which it is not as of today and we have no proof that it is.