Just a quick one for now: Is morality objective?
If morality is objective, then something is right or wrong regardless of whatever intelligent beings decide. God is an intelligent being. Therefore if morality is objective, something is right or wrong regardless of whether or not God decides it to be so. Thus God does not decide what is right or wrong, he merely communicates what he knows to us.
Now I'm guessing that most Christians will find that conclusion difficult to accept: of course God has a say in what is right or wrong, he's the Creator isn't he? OK, so let's make morality contingent. Well, bang goes the argument for the existence of God on the basis of objective morality!!
So if we're trying to understand morality, if morality is contingent, it could just as easily have been created by humans as by God. By Occam's principle, it is foolish to invoke a more complex explanation when a simple one will do. We must first look for a purely naturalistic explanation of morality, and only turn to a supernatural explanation when a naturalistic explanation is proven not to exist.
Conversely, if morality is objective, then God cannot be invoked as an explanation, as this gets us nowhere.