“I am speaking the truth in Christ–I am not lying; my conscience bears me witness in the Holy Spirit–that I have great sorrow and unceasing anguish in my heart. For I could wish that I myself were accursed and cut off from Christ for the sake of my brothers, my kinsmen according to the flesh.” (Romans 9:1-3)
Paul confessed that Jewish unbelief in the gospel of Jesus caused him anguish. He wondered how the chosen people could have rejected their own Messiah. He wondered if their rejection meant that somehow God has gone back on His promises, that He has acted contrary to His own nature. But Paul realized that God’s promises were not to national or ethnic Israel, but to the true, spiritual Israel, the Church. Just because a person is born a Jew and is circumcised, this does not mean he is a member of this true Israel. There was a remnant of Jews who had accepted Christ. Yet the majority had rejected Him choosing rather to pursue their own righteousness, prideful in their assumption that either they could keep the law to perfection or else resting in their national heritage as the chosen people assured of their righteous standing before the Lord no matter how they lived.
Paul maintained that the true elect of God are called from both Jews and Gentiles. This is true today. Therefore we believers are called to present the gospel to everyone we meet regardless of race, ethnic origin, or social status. We should feel as much sorrow for the lost as Paul felt towards the Jews and he felt unceasing anguish indicating that His sorrow troubled him deeply. We, like him, should do as much as possible to tell all unbelievers of the love Christ has for them so they would come to faith in Him.