"[Attack] the Amalekites and totally destroy all that belongs to them. Do not spare them; put to death men and women, children and infants, cattle and sheep, camels and donkeys."This is the first genocide that is recorded in history, so far as I know. It is a "final solution" far more complete than that of Hitler against the Jews. It has important ethical considerations with regard to Christianity. Specifically, any form of Christianity which is literalist enough in its interpretation of the Bible such that Samuel's command to Saul to slay the Amalekites was in fact a command from God is committed to the view that genocide is sometimes the morally correct thing to do. Indeed, given that the 'offense' of the Amalekites was to attack the Israelites as they sojourned from Egypt (Exodus 17), even moderately literalist Christians are committed to the view that genocide can be the morally correct thing to do based on the actions of the forebears of a people, 13 or more generations beforehand.
It is important to understand what I am saying here. I am not saying that Christians are committed to accepting genocide in general as being morally blameless. I am pointing out that for at least one genocide, literalist Christians are committed to believing that the genocide was not just acceptable, but laudatory. So laudatory that failing to actually kill all the domestic livestock of the people was grounds for a punishments those Christians must also regard as just. And because the genocide of the Amalekites must be considered laudatory, those Christians are committed to believing that at least some genocides are morally laudatory as a matter of logic.
This is not the only morally confronting aspect of literalist versions of Christianity. Deuteronomy 22:13 ff gives a series of law covering sexual relationships outside marriage. They specify that:
1) If a man sleeps with a married woman other than his wife, regardless of whether the act was consensual, both must be put to death;
2) If a man sleeps with a woman who is betrothed to a person other than himself; if it occurs in the city both must be put to death (because the lack of outcry is presumed to indicate consent); but if it occurs in the country, only the man is to be put to death (for it is presumed the woman did not consent, but that her pleas for help went unheard); and
3) If a man sleeps with a woman who is neither married nor betrothed, then he must pay a fine and is compelled to marry the woman regardless of wither the original sex was consensual, and regardless of the consent of the woman to be married.
That may be a little controversial. Some people have argued that Deuteronomy 17: 28 and 29 (which covers case (3)) only applies in the case of consensual sex. That interpretation, however, would mean there is no biblical law covering the case of the rape of a woman who was neither married or betrothed. So, it escapes the morally odious implication that woman are compelled to marry their own rapists by making it the case that rape of unmarried, unbetrothed woman was not illegal at all, and carried no penalty in biblical law. That is, they make the law yet more odious.
Finally, Leviticus 20:13 states:
"If a man has sexual relations with a man as one does with a woman, both of them have done what is detestable. They are to be put to death; their blood will be on their own heads."Thus a literalist Christian is committed to believe, not only that homosexual activity (in men only) is a sin, but it is a sin heinous enough as to deserve the death penalty. Indeed, as the standard method of execution in the Old Testament is stoning, a death penalty imposed in a particularly cruel and brutal way.
I need not point out that all four of these moral judgements - that genocide is sometimes laudatory, that unbetrothed, that married woman who are raped should be executed, that unmarried woman should be forced to marry their rapists, and that male homosexual activity is an immoral act so heinous as to deserve death are quite contrary to the commonly accepted morality of the West. So much so that many Christians who consider themselves literalist (or close approximations thereof) will reject the plain words of the Bible, and the immediate logical implications of those words when confronted with them - seeking all sorts of ways in which the text does not say what the text says, but is actually in accord with the commonly accepted morality of the West. That they add to the Bible by making all sorts of speculative assumptions to justify the material does not seem to bother them.
The most common and most principled attempt to escape these implications is to argue that Christians are not under the Old Testament Law, but under Grace. Superficially, that attempt has substantial justification in the writings of Paul the Apostle. The argument fails, however, on two points.
The first, and most essential point is that I am not pointing out that Christians are required to obey the Law today. Rather, they are merely committed logically (to the extent that they are literalists) to believing that the Law was good, and that the prophets (including Samuel) spoke for God. And if they accept that, they are then committed to genocide being at least some times morally laudatory, to the belief that typically, it is just to kill a married woman for being raped; that typically it is just to force an unmarried, unbetrothed woman to marry her rapist; and that it is just to kill homosexuals for their homosexuality. It is not that they must kill homosexuals, etc; but that if the civil law required it to be done (as it did well into the 19th century in England), that that was just and right.
The second point is that the Law has a role in Paul's theology. It acts as a tutor. It was imposed to teach the Israelites and by extension, Christians, what God considers just and right. And even though in Paul's theology, Christians are under grace, they are only under grace if they both repent and believe. Repenting, of course, means turning from a secular ethic to God's purportedly perfect ethic, as taught in the Old Testament. Ergo, to the extent that you are Christians under Paul's theology, you must also strive and pray for the grace to allow you to so change your ethic as to comport with the ethic that says Genocide is sometimes laudatory, etc.
Given these two points, the claim to be under Grace rather than the Law (while definitely a Pauline theology) does not exempt Christians from the odious implications of Old Testament law.
There are atheists who consider points like these (often stated more crudely, and hence incorrectly) as rebutting Christianity. I do not do so. It is possible to be a non-literalist Christian - a Christian that takes John seriously when he identifies Jesus as the Word of God, which by implication means the Bible is not the Word of God, and hence cannot be supposed to be literally true. On such a view the Bible would still be important because it contains the historical documents which were produced as a result of Jesus' activity revealing God through history. That is, they are important source material with regard to the revelation, but not the revelation itself. There may be other problems with such a form of Christianity, but at least it does not render itself morally noxious from the start.
Further, despite these moral failings of a literalist Christianity, it does not follow that Christians have been (and certainly not in any particular case) a baneful moral influence on the world. Christians, as they are fond of pointing out, and as atheists firmly believe, are just human. They are likely to inconsistently interpret their scripture - and are as likely to do so in a way that errs on the side of good as on the side of evil. As a result, Christians can be found on both sides of any major moral conflict in the last one thousand years. They have stood both for and against slavery, for and against racism, for and against Nazism, and for and against marriage equality. Those Christians who have fought against slavery, racism, Nazism, and for marriage equality have been better than the biblical ethic requires.