We left off
seeing the thought flow of this first major theme, namely that the
grossest-sinner-and-unbeliever is in the same exact boat as the
moral-and-upright-unbeliever. This category of moralist includes, of
course, the Jew (as aforementioned). The Jew stood on the side of God
judging the sins of the people around him, clamoring at the evil found
therein.
This Jew found comfort, Paul would point out, on the fact of the Law
and the special relationship the Jew had with God (v17). The moralistic
Jew would boast in this relationship and in the knowledge of God’s will
regarding morality because the Jew received instruction from the very
Law itself.