When it comes to the debate of moral truth, can the ad hominem be avoided? It always comes to a theist questioning an atheist's morality and an atheist questioning a theist's morality. Since one's morality is the scale we measure the "goodness" of the person, we are basically saying that the individual we are debating against is a bad person. I don't like this, but since the only way to debate the validity of subjective morality is to call into question the moral beliefs of your opponent, I see no way around it.
Inversely, a theist will call into question my belief that homosexuality is not a sin. Or that I am immoral because I have had sex outside of marriage. Or that I'm immoral by default simply because I haven't accepted Jesus to wipe away original sin. You can hate the sin and not the sinner, but that doesn't change the fact that an immoral person is a bad person.
I understand that most of these debates deal with the hypothetical and not the practical, but I'm tired of talking about hypothetical bestiality. It's humiliating and insulting. It detracts from the point of the argument. Is there a god and did he give us our morality? Those that think that there is and he did, also think that said god gave us life, the universe and everything. So let's talk about that, because I'd like to think that we're all good people.