OK, it's a long time since I argued theology but here goes. Please accept my apologies if the follwoing wall o' text is a bit garbled or sounds like a sermon; I'm sort of thinking aloud, and thinking in the religious mode brings back rhetorical habits which I forewent two decades ago.
Mainstream Christian belief is that the Old Testament is not to be taken literally, either as a historical document or as a book of law. It is provided as a resource of traditions so that the teaching of the New Testament can be understood in context. Consequently, the OT contains not only the mythology of the Jewish people but also the development of their laws and also of their understanding of God. This has to be the case in any document that is collated over thousands of years.
No doubt someone will try and say, "Ah, but isn't the Bible supposed to be written as a result of divine revelation and therefore can't be false?" Well, I would say then, yes and no. The thing about divine revelation is that it is analagous to a parent talking to his or her child. When I explain things to my two-year-old son I use very different concepts and tones than I do when I explain to my sixteen-year-old daughter. With the two yeal old I am much more authoritarian and much less nuanced than when I talk to the sixteen year old. It has to be like that because no matter how intelligent my son might be (and like every father I hope my child is very intelligent indeed) he simply lacks the knowledge and experience to be able to cope with more nuanced understandings. Thus I tell him "Don't play with the electricity sockets, it's naughty, dangerous and you could die," while I am quite happy to teach my daughter how to wire a plug and discuss the relative merits of residual current circuit breakers and earth leakage circuit breakers. He life and experience allows her to access the deeper and more nuanced understanding.
So we look at the beginnings of the OT and we see documents that were written for a primitive and nomadic society. There may well have been some incredibly intelligent and talented people in it but, on the whole we're looking at a society that was just coming out of the stone age and into the Bronze age. In what way would such a society be able to accept or understand the concepts which guide our modern society? Much of what we consider to be necessary rules for civilised living would be met with blank incomprehension.
While the OT may not be particularly relevant to today's living, it is still important to see how the ideas therein developed. In doing so, we gain a better understanding of current ideas and are therefore better able to understand them. Thus we see a system in the OT which is excessively legalistic with a whole plethora of rules to cover every situation that the Isrealites might have had to deal with. As the society evolved, the philosophy changed from the authoritan one of the OT to one which requires greater understanding in the NT. All of the OT commandments (and there are a whole lot more than just ten) are condensed to the priciple of love: to love God and to love one's neighbour as oneself (for those obsessed with references you can find it in Matthew 22: 34-36, Mark 12: 28-34 and Luke 10: 25-28). This is the fulfillment of the law of which Christ spoke.
Living with a guiding principle which you have to interpret isn't easy; it's hard. There's none of the comfy certainty there that atheists often claim that Christians cling to, you have to work it out for yourself, which is scary stuff. After all, you might get it wrong. It's no surprise, therefore, that while much of the OT is set out as law, much of the NT is set as teaching, to furnish those that believe with the necessary understanding with which to apply the principle of love. Again, you can see this transition as you look through the OT, with the teaching in the Book of Proverbs and later in the Book of the Wisdom of Solomon (the lack of which makes protestant bibles all the poorer). It's not as expansive and is more authoritarian than the Pauline epistles but it shows the evolution of ideas.
So following that evolution of thought, Christianity is not meant to be a matter of blindly following rules. Judiasm was but Christianity wasn't. Christian's are called to be obedient to the principle of love but not blindly obedient to the laws laid down in the OT: that's why Christians can eat pork and don't have to be circumcised, to give but two examples. Inevitably, people will succumb to the temptation to go back to the legalistic living of the OT, after all people like certainty. However, in doing so, they move away from the Christian ideal and, if they start using their rules as clubs with which to batter and beat and otherwise bully others into conforming to their twisted version of Christianity, they are not fit to own the name, Christian.
In the end, it's not the Bible nor Christianity nor- to widen things- religion in general that makes people blindly follow rules, it's basic human nature.