Paul says, “But that no one is justified by the law in the sight of God is evident, for ‘The just shall live by faith.’” Then he immediately says, “Yet the law is not of faith…” (Gal. 3:11-12) The law is the perfect measure of human behavior and desires, first those toward God, then those toward his neighbor. Unfortunately, man was now a fallen sinner, sold under the dominion of sin. The Jews could not possibly obey God’s law. God’s purpose for giving Israel His law was to prove to the Jews the reality of their fallen condition in Adam. Mankind was proven to be utterly depraved. (This important truth and its associated implications are almost entirely missing from contemporary Christian doctrine).

More detailed information on this subject:

https://www.reintgenchristianbooks.com/chapter/chapter-religion-judaism/

https://www.reintgenchristianbooks.com/eternal-life-part/

https://www.reintgenchristianbooks.com/did-christ-fulfill-the-law-as-a-substitute-for-the-believer/

https://www.reintgenchristianbooks.com/desiring-to-be-a-teacher-of-the-law-then-take-the-teachers-competency-test/