Okay, before I start, I should mention that I am not a scriptural literalist. I see the Bible as a historically significant document written by men. If you see it as a divinely-inspired account of history, every word of which is literally true, some of this might offend you. But, not necessarily.
I do think I'm more accepting of the "illogic" of religion than most people who weren't raised in a faith. I was actually fairly surprised last year when the subject of the Bible came up among the TAs in World Civ. We have these sidewalk preachers who come on campus regularly to warn the students about the secular education they're receiving at Mall University. They're certainly annoying, and one of the other TAs had some reason to be particularly annoyed- a very similar religious fanatic apparently shot and killed his friend's father some years back. The father was a doctor; no points for guessing what field of medicine. Yet, I was somewhat surprised at just how negative their views were about the Bible. Not only did they find the religion offensive; they were both convinced that the scriptures are terribly written, mendacious, and impossible to take seriously if you're an adult.
I'd beg to differ. Not simply because I think the Old and New Testaments contain some truly exquisite poetry and prose, but also because their words are as central to Western literature as Shakespeare. It's nearly impossible to read anything of merit in the Western canon and not find some echo of the language of the scriptures. Indeed, it's hard for me to see how you could profess to teach Western Civ or World Civ without a fairly good understanding of what the Jewish, Christian, and Muslim scriptures say.
As for the illogical quality of the scriptures, well, faith is not based in empirical reason. It has to be illogical and contain a fairly healthy element of doubt, or it's not faith. (I think Kierkegaard was key for my understanding of this.) Faith is deeply illogical and even somewhat absurd. So, incidentally, is romantic love. Both are a matter of inner conviction. I believe that Claire and I have a metaphysical force called love between us, although I have no way of scientifically measuring it. I can feel it however. I would imagine that faith is much the same. If it could be proven empirically that there is a God, faith would cease to exist. (Probably a good reason to oppose creationist science incidentally)
When it comes to the Old Testament, it is even harder to take the scriptures literally. Some of these sections are downright bizarre and many of them are cruel and violent- something that comes to mind whenever I hear Jews and Christians talk about the crueler passages of the Koran. I can't imagine living in a society in which young women are stoned to death for lying about their virginity or committing adultery, or in which God speaks through his prophet to warn us about eating owls. Perhaps my favorite passage in the Old Testament is the rule in Deuteronomy that, if two men are fighting, and the wife of one man grabs his genitals to stop the fight (yes, really!), you must cut off her hand and show her no mercy. Please, someone explain the practical application of that rule in today's world!
Of course, very few people actually take these passages literally. There are fundamentalists who will talk about the passages in Leviticus about homosexuality, while ignoring the ones on shellfish. But fundamentalists are akin to the mentally disturbed or schizophrenic, trying to keep a logical system together in their head at the expense of all information from the outside world. They are, thank God, a minority among believers.
Instead, most believers see these scriptures as containing errors, metaphors, hidden truths, and myths. These books are the accounts of a particular tribe in the Near East and were written at least 2,500 years ago. I think it's best to see them as the ways in which that tribe explained itself and the world, and they likely contain a certain amount of mythologizing and self-aggrandizement. Christians, of course, see the New Testament as explaining a new covenant between God and man that supersedes much of what is in the Old Testament/Covenant. Christ also makes sin a purely individual matter; something many Christians seem to forget.
In terms of world history, what's important about the Old Testament is that the tribe is defined by its individual relationship with a single God through direct revelation. This revelation comes in the first books of the Old Testament in much the same way as the gods influence men in the Greek legends: it is direct and unequivocal. We are to understand that Yahweh is speaking directly to the patriarchs and giving them very clear instructions about what to do. He tells Abraham to kill his son, tells Moses to give specific warnings to the Pharaoh and so forth. In later books, God is more distant, but here we're talking about something like schizophrenia. If you want to see that as the way that the universe communicates with visionaries, so be it.
It is inescapable that Yahweh is cruel in these books. I have no words to explain killing the firstborn sons of Egypt for the sins of the Pharaoh, especially given the fact that the scriptures make clear that the defiance of said Pharaoh was the direct result of God "hardening his heart". Moses believes the Pharaoh has the choice to sin or not to sin; we the readers and Yahweh know that he does not. Therefore, his subjects are killed simply because God wants them to be in order to demonstrate His might. This pushes the idea of a vengeful God to the limit.
Therefore, I think the first message the writers wanted to put forth was that the Jews are the chosen people of God, and that membership has its privileges. Secondly, that God is all-powerful. A central message here is that fear of God is the beginning of wisdom. It is familiar from much of Greek mythology as well. Man is powerless in the face of the eternal. Note that in the first five books, the Pentateuch or Books of Moses, God punishes by killing and rewards by enriching his believers. There is little to no talk of Heaven or Hell, and nothing of an inner voice that knows good and evil. The image of Yahweh seems more akin to a primitive tribe trying to explain what their protector God must be like in the only language they have. This is the only way I can comprehend the vicious God in the Moses books of the Old Testament.
As for the ten commandments, they're much more comprehensible, with the exception of the indictment against graven images. It is not clear, at least to me, that the scriptures are not saying that Jews and Christians should make no art at all. Clearly, they shouldn't worship graven images; however, the commandment seems to be pretty straightforward about making no images of anything on earth. Islamic art, which generally does not represent human beings, seems more in keeping with the commandment. I'm not sure why this should be.
There are more detailed rules in Leviticus and Deuteronomy, but the aim of these first two books seems to be to set forth the story of the tribe and its covenant with God. That story, it should be pointed out, has more than passing kinship with the earlier Ugarit texts as well as the Enuma Elish. The texts most likely relate common stories from the region as well as a very traditional understanding of God: at this point, humans have no choice but to obey His direct commands or suffer the consequences. There is little nuance in these books and no jokes.
Again, absolutely none of this is to say that believers are fearful or ridiculous. I have very little in common with the Bill Maher school of scriptural criticism. Jews aren't defined by believing that bushes talk to people or that menstruating women should be exiled from the community. What they are defined by is the belief that human existence has distinct limits and rules that must be obeyed, and that there is a powerful creator God who maintains a covenant with His believers. None of this strikes me as naive or foolish, but only a matter of inner conviction.