"Mujus, you know what I mean, is it possible to have an objective debate with people who claim they know what God means or thinks."
Well, Nigee, I don't think most Christians claim to know a priori what God means or thinks. They think He revealed Himself in His word, though, and that's why they're quite serious about interpreting it. (In theory anyway. Of course we all fall short of this ideal sometimes). But in particular, they tend to interpret it under the assumption that it does, in fact, make sense, which is a pretty natural corollary of thinking that it was inspired by a loving and all-powerful God in order to communicate to us.
Lots of people like to say that it's arrogant to think we could understand God; in one sense it's true that we can never understand/comprehend God. But in another sense, it's really insulting to God to suggest that He couldn't communicate with His own creatures if He wanted to.