You are confusing the Hebrew scriptures with first-century Judaism. You are assuming that the Jews of the 1st century followed the Hebrew scriptures exactly. Paul would point out that the Hebrew scriptures themselves teach that God is satisfied with the faith of believers and that attempting to follow the law, and failing in the smallest point, subjects themselves to the curses in the law.
My point... and I get it from Paul...and from the author of Genesis 15...and from Habakkuk....and from pretty much the rest of the Hebrew scriptures... is that the Hebrew scriptures teach that when one believes God, it is reckoned to him as righteousness.
So, the only one who interpreted the Hebrew Scriptures correctly was Paul? Either Jews are incredibly stupid and never got their own Scirptures right, or they didn't think Paul was that smart. I would wager for the latter.
My point... and I get it from Paul...and from the author of Genesis 15...and from Habakkuk....and from pretty much the rest of the Hebrew scriptures... is that the Hebrew scriptures teach that when one believes God, it is reckoned to him as righteousness
God's commandments tell Israel what to do and what not to do in order to live a righteous life. The mindest is simp[ly that if you honestly try and honestly fail, God will consider it righteousness. No one expects perfection from imperfect beings. So, being unable to keep the law perfectly is immaterial. Your intention counts in righteousness.
Hebrew God demanded obedience, not faith. Christ rewards those who did "it to Me" in Matthew 28. Paul re-invented the wheel and sold it to the pagans, and saved the Church. That's all.