The principle of faith established
Is God the God of Jews only? Is he not the God of Gentiles too? Yes, of Gentiles too, 30 since there is only one God, who will justify the circumcised by faith and the uncircumcised through that same faith.
Recall that earlier Paul had spent considerable time on the subject of the Jews having an advantage by virtue of their covenant relationship with God regulated by the Mosaic Law. The Jewish advantage had been ruled out when Paul declared that God shows no favoritism (2:11). Here the apostle returns briefly to that subject. He agrees that if having and doing the law were the essence of a right relationship with God, then the Jews would have an advantage. But a right relationship with God does not rest on obedience to the law, but on having faith. Since such a right relationship comes by faith, it’s there for all believers, Jew and Gentile alike. Hence God is the God of Gentiles as well as Jews, because he will “justify the circumcised [Jews] by faith and the uncircumcised [Gentiles] through that same faith.”
Do we, then, nullify the law by this faith? Not at all! Rather, we uphold the law.
Paul has left no doubt that the law is not the basis upon which sinners are reconciled to God. That’s accomplished by faith alone. But does this mean that by extolling faith Paul is thereby nullifying, or rejecting, the law as though it were bad or useless? Paul responds, “Not at all! Rather, we uphold the law.” In subsequent chapters, particularly 6 and 7, Paul will have much more to say about the proper function of the law.
But for the moment he continues his emphasis on the priority of faith. He points us first to the case of Abraham.