Romans 10:16-21
Why did not every Jew become a Christian? The 12 disciples were all Jewish. The church came into existence on the day of Pentecost and all the new Christians were Jewish. The gospel, good news about Christ, spread out from Jerusalem into the entire known world. The early church was a Jewish church. In the years following, the church had become increasingly a gentile congregation. Increasingly the Jewish people had begun to reject the church and to reject Christ.
To respond in faith to the gospel, you must hear the message. The Israelites did not reject Christ because they had not heard. All of the first preachers were Jewish and they, including Paul, always delivered their first message in the synagogues. They taught that Christ was the messiah promised in Old Testament scripture. When Paul is writing to the church at Rome, all of Judaism had heard the gospel. Yet many had not accepted the good news.
They did not reject the gospel because they did not understand it. The gospel was so clear that the gentiles who were not even seeking God understood. God used the gentile response to the gospel in an attempt to move the Israelites to envy. When the Israelites saw the change the gospel made in the life of the gentiles, God wanted it to move them to desire the same in their lives. Instead, it only made them angry with God and at Christians.
God continued to be faithful to Israel. He continued to bear witness to them, but they were a stubborn and disobedient people. They rejected Christ, and the church lost much of its unifying identity with Judaism.
What was true for the Israelites then is still true today. People have heard the gospel and God is still holding his hands out to them. God still wants Christians to live lives that make non-Christians envious. If our lives are righteous and blessed, they will produce envy. When we are what a Christian should be, others will want to be one.