My friend, Don Charles, has an excellent three part post entitled, "How to Beat the Bible Beaters," that he just put on his excellent blog, Christ, The Gay Martyr. His three part post deals with the reason that religious homophobes all too frequently seem to be winning the argument regarding same-sex love, and that is largely due to the fact that they rely on simplistic sound bytes that appeal to the conservative or even reactionary bent of their audience, while what LGBT rights activists frequently rely on are long-winded explanations giving arguments that make it appear as if many of them don't even seem to believe in their own arguments.
He also deals with the assorted arguments that professing Christian homophobes use and the quick comebacks that those who would debate them can use in winning the argument, while not offending the intelligence of the audience. He makes it clear that sweet reason will never win over a homophobe, but that that homophobe with whom one is debating can be put in his/her place by asking certain fundamental questions, and/or by making one sentence rebuttals to their arguments that will both capture the essence of their bankrupt views as well as make the argument for the validity of same-sex love clear to all who will listen.
I strongly urge you to read this three part post on his blog so that you can be armed with the ammunition necessary to show to all who will listen the vacuous and untrue one-liners that reactionary forces who argue against the legitimacy of same-sex love all too frequently use to bolster their insupportable positions.