That's the problem with debating religion, period. Invective is pretty much the pinacle of the debate. Few minds are ever changed. The older and wiser I become, the more I realize that if conversion is possible it has to come from love, not debate.
Sometimes it's a loving thing to point out to a person that they aren't consistent with what they believe, or that that there are holes in their world view that they may not have considered. Jesus engaged in debates with religious leaders of His day and He essentially said "It isn't about religion, it's about a relationship between you and God, not how many religious duties you have performed."
That being said, what's a soft atheist?