This is an interesting point. If you in fact actually want to know about one’s beliefs, why would there be any “arguments” to use? Intending to argue with a believer belies respectful discussion of belief, so you may as well give up the attempts to be “respectful” at the outset. In fact, a hidden agenda is probably going to be looked at as more jerkish behavior then being upfront with the purpose of your discussion.
I’m vaguely christian. Though I believe in (many of) the tenants of Christianity, I don’t believe there’s a value to organized religion so I don’t adhere to any church.