Really? Just as an example, show us how many of the 10 Commandments are codified into U.S. Federal law. Please cite actual court cases and majority judicial interpretations.
Quite a few are, but obviously not all of them. Here are some I know are, and can dig up court cases if you wish, but I think you will already agree with me.
Aseret HaDibrot - The Ten Commandments
1. Belief in God - No
2. Have no other Gods - No
3. Not use the Name of God needlessly and not breaking oaths - The first half no, second half yes. Oral contracts are binding, oaths in court are binding
4. Keep the Sabbath Holy - Christians (due to the machinations of Emperor Constantine) incorrectly think Sunday is the Sabbath Day. Due to this, there were many laws against selling on Sunday. These have mostly been removed, though some remain.
5. Do not disrepect your Mother and Father - No, but we need this.
6. No Murder - Yes
7. No Adultery - Depends on the state, some have adultery as a crime still.
8. No Stealing - Yes
9. No lying in court - Yes (Jews extend this one to ALL forms of Lashon Hara - evil tongue, in that sense some of it is, some is not).
10. Do not covet - Partially. Covetting is to desire something so fully you will go to any length to get it. The act of covetting is not illegal, but a great many of the actions done due to covetting are, such as stalking, murder, rape, etc.
It is a mixed bad for codification into law.