However, given that many put their money on the Bible being a revealed text, given that there are people willing to die for what they believe is the word of God, and people willing to kill for what they believe is the word of God, it does matter a great deal, even if those are the extremists we're talking about.
What about the (comparatively) more mundane rules that govern how some live their lives? Is divorce ever acceptable?
Whosoever shall put away his wife, and marry another, committeth adultery. -- Mark 10:11
Whosoever shall put away his wife, saving for the cause of fornication, causeth her to commit adultery. -- Matthew 5:32
When a man hath taken a wife, and married her, and it come to pass that she find no favour in his eyes, because he hath found some uncleanness in her: then let him write her a bill of divorcement, and give it in her hand, and send her out of his house. And when she is departed out of his house, she may go and be another man's wife. -- Deuteronomy 24:1-2
Which is it? People live their lives according to these things.
Should Christians keep the OT laws?
Matthew 5:18-19
Till heaven and earth pass, one jot or tittle shall nowise pass from the law, till all be fulfilled. Whosoever therefore shall break one of these least commandments, and shall teach men so, he shall be called the least in the kingdom of heaven.
Romans 10:4
Christ is the end of the law for righteousness to every one that believeth.
Etc. etc.