Orthodox Jews are very serious and very faithful to do all that the rabbis tell them to do. Since the destruction of the Temple in 70 CE, there has been a continual change of interpretations and traditions, all trying to keep the law of Moses as best as possible.
But Paul, the most sincere of the rabbis of his time, recognized that sincerity and works under the law will never be sufficient to be acceptable before God.
Now we know that whatever the law says, it says to those who are under the law, that every mouth may be stopped, and all the world may become guilty before God. Therefore by the deeds of the law no flesh will be justified in His sight, for by the law is the knowledge of sin.
PRAY FOR ALL ISRAEL TO BE CONVICTED OF THE IMPOSSIBILITY OF BEING RIGHTEOUS THROUGH WORKS.