I just don't see where a Christian ethic based in a divine commander has any fewer problems than a Godless ethic, especially when Christians have understood so many different ways of obeying those historically conditioned commands down through the centuries. It just looks like a human enterprise to me, which has similar serious problems.
What we know is that down through the ages we have all come to better understandings about how to get along in our world. Not that there are still backward people who want to blow up abortion clinics and become suicide bombers, only that civilized people are, on the whole, better people than those of the past. There have been certain ethical improvements over the years which makes Hitler look better when compared to Genghis Khan; our problems with regard to racism seem "slight" by comparison to the evils of slavery in the South (and sanctioned from the Bible); and we no longer lynch people without a trial (when convicted, our death penalty is that we simply put them to sleep); the problem of equal pay for equal work for women is small when compared to the day when women couldn't vote and were regarded as chattel. With each successive improvement Christians began reading the Bible in light of these social developments, but for the most part they were against every one of them. Present day Christians stand on the shoulders of earlier Christians who interpreted the Bible in inhumane ways, and yet they claim they wouldn't have done so. That's just not probable.
So where does that leave us? In the same boat. Trying to get along with one another, to live decent and happy lives with one another the best we can. The problem is that Christians (and other religions of the book) believe the way we should live our lives is commanded and sanctioned in the Bible. That's the only difference. I think such a claim is a farce, given the history of the church. Just because Christian ethics have evolved in the same direction as civilized society has traveled doesn't mean the Christian can claim her ethic is better. I think a strong case can be made that the way society has traveled in turn changed how the church interpreted Biblical ethics, not vice versa.
Christians repeatedly argue that as atheists we have no reason not to murder others, or create mayhem. They claim we don’t have an ultimate standard for knowing right from wrong, or for abolishing such things as slavery.
But Christians are not off the hook here. Christian, as a believer in God, upon what basis does your God make the ethical and moral judgments he's made? On what basis does he apparently seem to consider Hitler and Genghis Khan in the wrong?
The philosophical Euthypro dilemma applies wherever the buck stops, with us, or with your God. That's why Erik J. Wielenberg talks about eternal Platonic values, in his book Value and Virtue in a Godless Universe. You must assume some eternal standard that exists apart from God if you wish to continue calling God "good." For if the word "good" means anything at all when applied to God, it means he's conforming to some standards of goodness. If not, then God is, well, God. He can command anything and call it "good" simply because he commands it.
So, we're in the same boat. Christians just fail to see it. It's ignorance on their part to say otherwise. Some things are just obvious, and that's all one can say about them.
Again, the bottom line is that Christians cannot say God is "good" without comparing him to a standard that is outside of himself, otherwise all they can say is that God is, well, God, and that's it. The characteristic of goodness is meaningless to God. God does what he does and calls it "good," no matter what he does. Anyone, including God, can call his actions and commands "good," if he defines the word good.
For all you know God has done evil in the past, or presently does evil, or will do evil in the future and simply call what he does "good." At that point we have no clue as the precise definition of the term as ascribed to God except to see how he behaves (and when we look at this world it doesn't look like God is good all). The fact that Christians believe God "doesn't lie" because he says so, doesn't mean he cannot lie, since whatever he does is by definition "good." If he lies about not lying and calls it "good," there is nothing we can say against his actions because he defines the word. Christians have no basis for believing what he says...none. God is, well, God, and that's it.
And to think Christians complain because as an atheist I don't have an “ultimate” standard for morality. Christians have no ultimate standard of morality too! No one does, not even your God.
So don't go pontificating to me anymore about how atheists have no reason to commit murder and mayhem if you cannot exonerate your God from doing likewise. If Christians want to maintain that God can do whatever he wants to us, then it merely means he's more powerful than any of us. It doesn't mean that what he does is truly good.
There is no ultimate anything, for anyone. Christians only claim the moral high ground. But claiming something doesn't make it true. They haven't been fully consistent or forthright about what it means to say God is the ultimate standard for goodness. It doesn't make any rational sense, the only sense God purportedly created in us, which is all we have to assess the claim that he is the ultimate standard of goodness.
Either none of us do, or all of us do (located in eternal metaphysical moral truths)! It's that simple. Sink or swim, that's our choice.