This question (nice to finally have a name to associate it with) is a particular one that seems to come up a lot in my discussions with those who do not want to believe. They first make the basic question, then point out that God has commanded “all sorts of terrible things” and questions what would happen if He were to command them again.
In one such conversation, my friend wanted to know what I would do if God commanded me to kill someone else. I assured my friend that He would not so command me, and if I were to receive such a declaration, I would be assured that it was not from God. He altered his statement; now I had absolute assurance that it was God speaking to me. To him, this set a kind of philosophical trap: either obey God and do something that He previously instructed was evil, or obey our own sense of right and wrong, thus nullifying any claim of obedience to God.
The chief problem from the argument is two-fold:
First, we do not see the fullness of creation as God sees it, and therefore cannot judge it as He does. However, as C.S. Lewis points out, we must be able to distinguish good acts if we are to mean anything by calling God good. This is an act that we must take on faith, by observing what we know of God’s actions to this point and His history with being trustworthy.
Second, people assume that God is capable of commanding a wide range of things because they have the experience of being able to change their minds. God does not change and therefore is not within our range of understanding. People assume that God could command an atrocious evil because He has changed, and they base that assumption on the observation that they change all the time. However, God cannot command the contradictory.
This ultimately leads to the only logical conclusion of the argument: It is good because God commanded it. It must be so, because God cannot command a contradiction, and we know that God is good. To claim that God does it because it is good is to place a power above God in determining what is good and evil. What is more, we are presuming to know more about good and evil than God does Himself. In that sense, we simultaneously proclaim that there is a power above God, and that we know more about that power than what we presently call God. What arrogant fools we can be.