27Where, then, is boasting? It is excluded. On what principle? On that of observing the law? No, but on that of faith. 28For we maintain that a man is justified by faith apart from observing the law. 29Is God the God of Jews only? Is he not the God of Gentiles too? Yes, of Gentiles too, 30since there is only one God, who will justify the circumcised by faith and the uncircumcised through that same faith. 31Do we, then, nullify the law by this faith? Not at all! Rather, we uphold the law.
Sinners are Jews & Gentiles
The Jews were just as guilty as Gentiles with resect to sinning against God. In that sense, circumcision is not a free ticket to righteousness - by itself it doesn't help.
All of us, whether Jew or Gentile, are justified before God by putting our faith in Him, and not by simply following His Laws.
None of us, in fact, is able to follow His Law so well that God could credit us as righteous on that basis alone, for all of us have sinned.