What does it mean to be grafted into the olive tree in the Bible?

In Romans 11, Paul uses the illustration of grafting to explain how Gentile believers are incorporated into the spiritual heritage of Israel. The olive tree represents God's covenant people, with Christ as the root. When Paul mentions that wild branches are grafted in, he emphasizes God's grace in extending salvation to the Gentiles, illustrating that these believers are now partakers of the promises given to Israel. This metaphor underscores both God's mercy and the unity of all believers, whether Jew or Gentile, in Christ, reminding us that the blessings of salvation are not earned but given through God's sovereign will.