Paul longs for his people, the Jews, to know the grace and forgiveness found in Jesus.
The Jews have the law, but Paul longs for them to understand that “Christ has put an end to the Law as a way of pursuing righteousness…Christ, not the Law, is now the means of righteousness for believers.” (Ben Witherington III).
Salvation involves someone being sent to tell the good news of Jesus. Then, some people hear that good news. Some of those people believe and call on the Lord. Salvation is the result. But, some who hear don’t believe, and Paul is deeply concerned because some are of his people the Jews.
Paul hopes that his people will become envious of the Gentile/Greek believers and realize that the way of grace and salvation belongs to them as well. Paul works through several Old Testament passages to form the basis of his concerns.