James Chastek discusses the morality in the Old Testament:

If our objection to the divine origin of Scripture is to call it a book of crude bronze-age genocidal goat herding patriarchal peasants, then do we expect something with a truly a divine origin be the finest fruit of a perfectly enlightened age, composed by leisured aristocrats, and reflecting the noblest, purest moral ideals and actions? Even if all these traits were compatible (non-patriarchal aristocracy?) an honest look at history tells us that such age would be marred by its love of its own atrocious actions and beliefs.  Our rhetorical jabs would just shift from whatever monstrous moral practices happen at the hands of goat-herders to the the ones that happen at the hands of enlightened, leisured aristocrats and college professors.

Is this missing the point, though? Sure, maybe out mocking of goat-herders is a little xenophobic and elitist, and maybe any culture God chose to reveal himself though would have its own vices and faults. But isn’t the heart of the objection that since God is “morally perfect” his revelation should be morally perfect? Isn’t this practically a tautology?

Of course any culture that God chose to reveal himself through would have its own vices and faults. And even if a revelation was morally perfect, there is enough disagreement about morals that people would criticize the revelation in moral terms anyway. But even the latter fact does not answer the objection, as Chastek acknowledges here, because the fact that people would criticize it anyway, does not mean that it in fact is morally perfect.

He continues:

Not necessarily. Instead of trying to justify the apparent moral degradation of Scripture we might investigate the hypothesis that some moral degradation is integral to its own account of revelation. Since it is complete in Christ, revelation is not just God’s speaking to human beings but speaking with a human voice. Given that God wanted to save human beings, and not just start again after the fall with a non-fallen creation (which would make both salvation and revelation unnecessary) he was committed to speaking with a fallen voice until such time when he would speak though his new creation in Christ. Demanding moral perfection of the revelation before this new creation would destroy the way in which Christ fulfills the Scripture as not just a revelation to humanity but through humanity.

Ultimately one would have to flesh out this thesis in order to give it a full consideration. What does it mean in particular for the Old Testament? Does it mean that parts of it are false? If not, what is the alternative?

And what does it mean for the New Testament? If revelation is complete in Christ, does it mean that the New Testament is in fact morally perfect, even though the Old Testament is not? As implied by Chastek’s first paragraph, people can and do criticize the morality found in the New Testament as well. For example, although Christ proposes an improved morality, he does not specifically distinguish what he is saying from pacifism, and consequently some early Christians were pacifists. Pacifism is not a perfect morality, and even if Christ might have personally understood this, he failed to make the distinction publicly, or at least failed to have it recorded. Likewise, many people have criticized St. Paul’s attitude to slavery, or the details of his view on the relationship of men and women.

As I said above, people would criticize even a morally perfect revelation. Consequently one possible response to such issues in the New Testament is to defend it in every respect, saying that in fact it is morally perfect. But this is possible much in the way that it is possible to defend the Old Testament in every respect, as for example saying that since God is the author of all, he has the right to command genocide, and that if it is commanded, people should carry it out. This answer is not impossible in itself. But if we do not wish to accept it because it is not a very reasonable position, I would suggest that the same thing is probably true about the New Testament, but with a difference of degree. The difference between the morality in the Old Testament and the morality in the New is not the difference between an imperfect morality and a perfect morality; it is the difference between a more imperfect morality and a less imperfect morality.

Whether one agrees that even the morality of the New Testament is imperfect, or asserts that it is perfect in contrast to the Old Testament, the resulting position will be consistent with holding the truth of the Christian religion. However, either response will have a price, basically because either response is a response to a legitimate objection. As for the exact nature of the price, I may revisit this issue in the future.