Galatians 2:16 yet we know that a person is not justified by works of the law but through faith in Jesus Christ, so we also have believed in Christ Jesus, in order to be justified by faith in Christ and not by works of the law, because by works of the law no one will be justified. 

The law of the OT was perfect. Because it was perfect, we could never follow every law that God gave to the Jews. Luckily, Jesus was sent for all people, not just the Jews. We can be saved through faith now, because our works will NEVER be good enough!
Aren’t you glad Jesus fulfilled the law?