Rom 11:25-32
In the Old Testament, Isaiah prophesied that the Israelites would eventually hear the word of God and return to God. (Isa 29:22-24)
Isa 29:22 Therefore thus saith the Lord, who redeemed Abraham, concerning the house of Jacob, Jacob shall not now be ashamed, neither shall his face now wax pale. 23 But when he seeth his children, the work of mine hands, in the midst of him, they shall sanctify my name, and sanctify the Holy One of Jacob, and shall fear the God of Israel. 24 They also that erred in spirit shall come to understanding, and they that murmured shall learn doctrine.
The people of Israel will be saved by believing in Christ, who is the mercy of God, not by keeping the law. (Rom 11:25-32)
Rom 11:25 For I would not, brethren, that ye should be ignorant of this mystery, lest ye should be wise in your own conceits; that blindness in part is happened to Israel, until the fulness of the Gentiles be come in. 26 And so all Israel shall be saved: as it is written, There shall come out of Sion the Deliverer, and shall turn away ungodliness from Jacob: 27 For this is my covenant unto them, when I shall take away their sins. 28 As concerning the gospel, they are enemies for your sakes: but as touching the election, they are beloved for the father's sakes. 29 For the gifts and calling of God are without repentance. 30 For as ye in times past have not believed God, yet have now obtained mercy through their unbelief: 31 Even so have these also now not believed, that through your mercy they also may obtain mercy. 32 For God hath concluded them all in unbelief, that he might have mercy upon all.