What does Romans 10:19 mean?
Paul has boldly declared that faith comes by hearing the word of Christ (Romans 10:17). So why didn't Paul's people, Israel, believe in Christ? Paul asked in the previous verse if it was because they did not hear the truth about Jesus. He rejects that idea. By the time Paul wrote this letter, the gospel had traveled all over the lands of Israel, and was traveling to the ends of the world.Now Paul asks if maybe Israel heard the gospel but did not understand it. Maybe they misunderstood the truth that God is accepting all who come to Him by faith in Jesus. Paul rejects this idea, as well. He quotes from the second half of Deuteronomy 32:21. The first half of that verse describes God's words about Israel way back in the days of Moses: "They have made me jealous with what is no god; they have provoked me to anger with their idols." In other words, God says symbolically that Israel's worship of non-existent gods caused Him to become angry and jealous.
He declares what His response will be in the second half of the verse, quoted by Paul here: God will make Israel jealous and angry through her relationships with non-existent, foolish nations. Paul points to this passage from Deuteronomy as evidence that Israel has understood since her earliest days that God would eventually welcome the non-Jewish nations. In fact, Paul insists, that's exactly what God has done in saving the Gentiles who trust in Christ.