The Exposition
(All Greek and Hebrew References are from the Strong's Concordance)

We are instructed by James to not just sit and 'hear' the Word but we must also 'do' what the Word says (James 1:22) . This is our works which brings to life our faith (James 2:26)

Those persons who do not know the law, have by nature done the things in the law.  This gives substance to the Romans 1:20 that says that we should see and know that there is indeed a God...   and we're without excuse if we refused (Romans 1:20) . Of course, we will all be judged (Revelation 20:12-13) .

Paul recognized here that the Gentiles were living more according to the New Testament Law (love) than were the Jews who still were clinging to the Old Testament Law and boasting about it (Old and New Testaments , God's Law) .

Paul was letting the Jews know that they were not where they should be with God because though they live according to the Mosaic Law, they are not living according to the Doctrine of Christ (2 John 1:7-11;  1 John 2:22-23) who being the epitome of Love, fulfilled the Mosaic Law (1 John 4:7-8;  Romans 13:10) .

Ultimately, every individual must live according to the same law of God...  Love.  All have the same chances and all will be bound to and judged according to the Law of Love and Liberty.  God is an Equal opportunity Savior.