If your argument comes from faith/culture, I think it's best to state that it's a faith based position. I mean, the danger is that when people argue from a faith-based platform but feel they need to have a more cogent argument it sort of becomes an argument where you have the answer and you're looking for evidence rather than vice versa, which doesn't work. Faith-based positions are by no means unacceptable in a debate, but in my opinion at least come off better and more reasonable when displayed as what they are.