I'm just bewildered by the way this thread keeps drifting back to interpreting scripture, as though the answer could be found in there. It's artificially stacking the deck and doing so in a way which actually alienates the majority. What marriage is or isn't has bugger all to do with Christianity, the Bible or the church.
I think that's mainly for the benefit of @Dayton3 since it's the only thing you can have at least some chance of debating with him over the issue. I keep wondering why he puts so much faith in a 2000 year old collection of books that have been poorly translated into English by people with specific agendas. I personally figure that showing him that the Bible doesn't always say what he thinks it says is the best way to get him to open his mind. Though, I know it's a long shot.