Romans 11
Their loss, our gain.
V11: "...salvation has come to the Gentiles to make Israel envious." That is humbling.
However, when the Israelites repent and becomes a disciple of Christ, their reward is far greater than the Gentiles.
V20-21:"Granted. But they were broken off because of unbelief... For if God did not spare the natural branches, he will not spare you either."
V22: "...[God's] kindness to you, provided that you continue in his kindness. Otherwise, you also will be cut off."
Again, a continuing comparison of the Israelites and the Gentiles.
What our roles are and ultimately, be grateful and continue in God's kindness.