But the primary goal shouldn't be to try and change the persons mind but to get them to think.
Correct me if I'm wrong, but are you suggesting that it's more important for this person to be an atheist who is against gays rather than a christain who supports gays?
Your solution:Question his beliefs and ask him why he believes what he does. The questions will likely be faced with either being completely ignored, answered with a dodge, or given an answer that can be easily proven wrong. However it might get the person to begin questioning there own views. Or another person with similar views but is more open minded might see it and it may play an indirect roll in changing the views of another person.
I suppose that could work. If you can manage to persuade this person to stop beleiving blindly in God, chances are you'll be able to persuade him that homosexuality isn't bad.
If for some reason he continues to act against gay rights, then he's probably using flawed data. Maybe the data isn't flawed. Either way, you're back to square one. The only difference is his reasoning behind his actions, which results in the same ending -- one more person against gays. But if you're ok with him being anti-gay, as long as he is using something other than God to justify his views, then I can't argue against that.
As great as the above sounds, there's one problem. When you tell a person they are wrong, they remain steadfast in what they beleive.
If you try to convince this person that God doesn't exist, he will more than likely refuse to even consider what you have to say. Remember, everyone beleives themselves to be right in the heat of the moment. For you to say "God doesn't exist" is the same as saying "you're wrong." Nobody likes to be told that they are wrong, and rather than admit that they are wrong, they will fight to protect their views, even if it means using flawed logic or manipulated facts and opinions. It's human nature, atheist or otherwise.
Let me clear things up with my solution.
My solution:Here's something you should remember about debates, you can't win people over with logic alone.
My goal is to persuade this person to stop supporting anti-gay activities. I know that they are strong followers of God. First, I must talk to this person away from the influence of others, especailly other anti-gay activists. I conceal my intentions and talk to him about his faith in God. I find things that we do have in common (or things I can pretend to have in common with him), such as the wickedness of drugs, the evils of cheating on your spouse, or the importance of the church. I would ask him questions and smile. I would say things I know he wants to hear. If I can get him to say yes after yes after yes, he will begin to see me as an intelligent person that he can relate too.
Great, now he trusts me. People are more willing to question their views when confronted by people they trust. This can be a slow process, but I can begin talking to him about gay-rights. I can suggest to him that homosexuals aren't all that bad. I would have to be subtle, but if he hasn't said no to me up to this point, it will be hard for him to break the pattern. I could talk about the rights that people have to be happy. Then I could slowly move in talking about homosexuality and how disgusting it is. Then I can suggest that it's their right and their life, as long as they stay away from me. If the activist does dissagree, chances are he will do so respectfuly.
Obviously, there are different things I can do to get him to change his mind. If he doesn't then at least he will be more open to the next person who is against homosexuality. If he's an extremist, then I would have to take him out some other way.
The way to persuade people, which I don't do very well over the internet, is to appeal to their inturests. You slowly make suggestions that they agree with and when they agree with something they originally were against, you make it sound like it was their original idea.