God no longer deals with the Jews as a nation. Because of their unbelief he has cut them off (Matt. 23:37-38; Rom. 11:20). Without question, God sovereignly rules the nation of Israel, just as he rules all others, in his providence. And any Jew who believes on Christ is saved, just as any Gentile who believes. But God has forever forsaken both Judaism and national Israel because of unbelief.
"The Israel of God" is not that little nation over in the middle east. "The Israel of God" is the church of God's elect, the house and temple of the living God, scattered throughout all the nations of the world and ages of time. The Israel of God is made up of redeemed sinners out of every nation, kindred, tribe and tongue, who believe on the Lord Jesus Christ. We who believe are the circumcision (Phil. 3:3; Rom. 2:28-29), the people of God's covenant (Heb. 10:15-17), the chosen and blessed nation of God's elect (I Pet. 2:9-10). God's church, his elect, are that Israel that shall be saved when "the fulness of the Gentiles be come in" (Rom. 11:25-36). God's church, "the Israel of God," will be complete when all the elect Gentiles as well as elect Jews have been brought to Christ by his almighty grace (John 10:16). Salvation and grace are promised not to Abraham's physical seed, but to the spiritual seed of covenant promise (Rom. 9:6-8).