The Jews tried, as many people do today, to attain the kingdom of God by works. Salvation has not worked that way in previous millennia, and it won't work that way now. We are justified by faith, and faith alone, and not by works lest anyone should boast about those works for all of eternity. Instead, we need to be boasting about what Jesus did for us on the cross for all of eternity! Where is boasting then? It is excluded. By what law? of works? Nay: but by the law of faith. Therefore we conclude that a man is justified by faith without the deeds of the law. Romans 3:27,28 Therefore being justified by faith, we have peace with God through our Lord Jesus Christ: Romans 5:1 For by grace are ye saved through faith; and that not of yourselves: it is the gift of God: Not of works, lest any man should boast. For we are his workmanship, created in Christ Jesus unto good works, which God hath before ordained that we should walk in them. Ephesians 2:8-10