Romans 11:28-32
28 Concerning the gospel they are enemies for your sake, but concerning the election they are beloved for the sake of the fathers. 29 For the gifts and the calling of God are irrevocable. 30 For as you were once disobedient to God, yet have now obtained mercy through their disobedience, 31 even so these also have now been disobedient, that through the mercy shown you they also may obtain mercy. 32 For God has committed them all to disobedience, that He might have mercy on all.
28 Concerning the gospel they are enemies for your sake, but concerning the election they are beloved for the sake of the fathers. 29 For the gifts and the calling of God are irrevocable. 30 For as you were once disobedient to God, yet have now obtained mercy through their disobedience, 31 even so these also have now been disobedient, that through the mercy shown you they also may obtain mercy. 32 For God has committed them all to disobedience, that He might have mercy on all.
The Jews were opposed to those in Christ when this was written, so were as enemies to the gospel, yet as a nation were still among the elect. God made promises to Israel and also to all nations through them - this does not negate nor replace Israel, but adds other nations to His chosen ones. We both have been born in sin and turned away from Him until called out to Him and away from sin. There is not one righteous, so we must be humble. So when he handed them over to disobedience, we of the nations were able to obtain the same mercy and grace as we await God to have mercy on them.