For the sake of argument, say that the God of the Christian Scriptures does exist--and has spoken. Shouldn't that influence...everything? I believe he does, and he has--so cannot justify leaving him _out_ of the equation. (In fact, I'd have a hard time justifying _equations_ at all--but that's beside the point.)

This is kind of the argument of _presuppositional apologetics_ -- no one argues from a position of 'neutrality.' We start with God, we end with God -- or we start rejecting him, and end without him too. At the top rung of every logical chain of argumetn is that principal starting point: God is, _therefore_... or God is not, _therefore_... Dostoevsky got at the heart of this when he said, "If there is no God, then all things are permissible."