Should we try to legislate the Bible in today's society?
It's not inappropriate to seek to apply the Bible, provided that we apply it wisely. And the wisdom lies in realizing that—since coerced faith and coerced obedience are unbiblical—the Bible itself provides the guidance and the ground for making space for a culture in which people have the right to choose which moral elements they will or will not obey. It sound almost contradictory. In other words, the Bible insists that there must not be coercion for every single moral command that it contains.
For example, "Thou shalt not covet." Are you going to make that into a law? No, because coerced non-coveting won't work. It's a self-contradiction. It's the same thing with belief in Jesus. The Bible clearly commands, "Believe on the Lord Jesus Christ and you will be saved." Should we turn that moral religious command into a moral law? No, because a law-constrained faith in Jesus is unbiblical and has no validity. Therefore, in a sense, the Bible shows that we should not turn all of its commands into law.
So your question boils down to, Well, which ones then?
Don't kill? - We all agree on that one. Make that a law.
Don't steal? - We all agree on that one. Make that a law.
Don't commit adultery? - Hmm. Now what about that one?
Remember the Sabbath day and keep it holy? - We used to have laws about that.
The way it works practically is that for the laws where we can get overwhelming consensus in the culture we're going to use coercion. The irony is that we believe in using coercion as a culture for the things that don't seem to matter very much. For example, I've got to get all the dog poop out of my back yard or I'm going to get cited, and coercion will be used to make me cut my grass or clean my yard. And yet, we can't use coercion legally to save a baby's life if he is still in the womb.
What we need to do is find those things in the Bible that we believe should be lived by, and then try as Christians—through preaching, teaching, and prayer—to bring about as much consensus as we can. And yet we will not press for the legislating of things where there is massive unwillingness to do it, because we would wind up making coercion the ground of our morality.