I tell the truth in Christ, I am not lying, my conscience also bearing me witness in the Holy Spirit, 2 that I have great sorrow and continual grief in my heart. 3 For I could wish that I myself were accursed from Christ for my brethren, my countrymen according to the flesh, 4 who are Israelites, to whom pertain the adoption, the glory, the covenants, the giving of the law, the service of God, and the promises; 5 of whom are the fathers and from whom, according to the flesh, Christ came, who is over all, the eternally blessed God. Amen. — Romans 9:1-5.
Paul explains his great sorrow for the lost state of his fellow Israelites — the Jews — in spite of their having all the privileges of God, and His revelation, including the promise of Christ’s coming in the flesh as the ‘eternally blessed God’. Such is Paul’s sorrow and grief that he could wish himself accursed if they could be saved.