It ain't those parts of the Bible that I can't understand that bother me, it is the parts that I do understand. --Mark Twain
Assumptions
Let's assume for the sake of argument that the God of the Bible does exist. How can we determine whether it's moral to obey Him?
If one defines "moral" as "whatever God says," then it's tautological that we must obey. So let's assume that "moral" means something else, something that most of us basically agree on even if we can't articulate. Something based fundamentally on human empathy for each other and, to a lesser extent, for other animals.
If "moral" isn't defined as "whatever God says," but we know that God is all-good and all-knowing then we must obey Him nevertheless. However, if we know that god is not all-good or that He is not all-knowing, then we must question whether obeying Him is moral. It's possible, after all, that God is evil, that He created us in order to amuse himself with earthquakes and war.
Let's stipulate that He is all-knowing, or at least that He knows more than we do, since this would be true of any reasonable definition of God.
The Question
The only question remaining is, is God all-good? Since we're working from the assumption that the word "moral" is not synonymous with "whatever God says," we must use some criteria for deciding whether God is moral, and judge Him by His words and actions.
The Evidence
Since the God we are discussing is the God of the Bible, then we have his words, and if we believe that God created the Universe, we have his actions. Can we prove that God is all-Good from either of these two sources? I don't think so -- each provides material which at least raises doubts. In the Bible, God commands animal sacrifice, he kills every person and animal on Earth except those allowed into Noah's Ark, orders the killing of anyone who violates the Sabbath, orders the killing of blasphemers, orders the killing of the Midianite women and children and "taking" of their virgins, the killing of worshipers of other Gods, the killing of non-virginal brides, etc. (Find these and more at the
Skeptic's Annotated Bible.)
Similarly, the world, which He created, is full of suffering -- rape, murder, sickness, natural disasters.
Conclusion
It might be possible to justify the actions and orders found in the Bible and the horrible circumstances found in the world, but we must acknowledge that we cannot simply assume that God is all-good based on His Book or on the universe. Nor does any amount of goodness in the Bible or in the world exonerate God of his questionable words and actions -- a doctor who saves thousands of lives but cruelly murders his wife cannot be said to be all-good. It may be -- however unlikely it seems to me -- that God has some divine plan that makes everything that appears bad to us part of a larger good, but we cannot make this assumption without assuming what we are trying to prove -- that God is all-good.
What are we left with? We cannot know for sure that God is all-good, so we cannot know for sure if following his commandments is moral. We must decide on a case-by-case basis what we shall follow and what we shall disobey.
In the absense of evidence of God's morality, I maintain that it is moral to disobey commandments which we deem immoral. If God spoke directly to me and told me to murder an innocent child, I would be forced to disobey. Similarly, I could not support Biblical laws which I believe immoral -- even assuming I believed in both God and the divinity of the Bible.
(Hat tip to Sadie Lou for suggesting this topic.)