What shall we say then?—that the Gentiles who did not pursue righteousness obtained it, that is, a righteousness that is by faith, but Israel even though pursuing a law of righteousness did not attain it. Why not? Because they pursued it not by faith but (as if it were possible) by works.
Romans 9:30-32a NET
What is the role of faith in God’s election? This is a debate that can be divisive. And Romans 9 is a key chapter in this debate. In the initial eight chapters of Romans, Paul described the gospel he had been proclaiming wherever he went. And he made clear the central role that faith played in salvation. He went on in the following three chapters to address the current unbelief of the Jews.
Paul began by expressing his grief over the unbelief of the Jews, his own people. He even went so far as to express a willingness, if it were possible, to be cut off from Christ if it would result in their salvation (Rom. 9:1-3).
He then made it clear that descending from Abraham was no guarantee of inclusion in Israel, the people of God (Rom. 9:6-7). God sovereignly chooses who he will, for whatever purpose he chooses. He chose Jacob and rejected Esau (Rom. 9:9-13). And he chose the Pharoah of the Exodus to play the part he did (Rom. 9:17). Paul is clear that election is not a matter of human effort or desire (Rom. 9:16). It is a matter of God’s mercy (Rom 9:15, 18).
Paul then summarized the condition of Israel, starting with “What shall we say then?” The Gentiles, who did not pursue righteousness, had obtained it. But the Jews, who pursued righteousness via the law, had not. Why was this the case? Was it just because God had chosen one and rejected the other? No, faith played a part. Those who obtained righteousness did so by faith. Those who sought righteousness in some way other than faith did not receive it.
This role of faith is fully in line with the gospel Paul described in the opening eight chapters of Romans. Salvation is a gift of God that is received, not by works, but by faith. God, in his mercy, sovereignly chooses all who come to him by faith.