GOD has not given up on Israel and Israel is not lost beyond redemption. A blood Covenant can not be broken.
25I want you to understand this mystery, dear brothers and sisters,£ so that you will not feel proud and start bragging. Some of the Jews have hard hearts, but this will last only until the complete number of Gentiles comes to Christ. 26And so all Israel will be saved. Do you remember what the prophets said about this? A Deliverer will come from Jerusalem,£ and he will turn Israel£ from all ungodliness. 27And then I will keep my covenant with them and take away their sins.£
28Many of the Jews are now enemies of the Good News. But this has been to your benefit, for God has given his gifts to you Gentiles. Yet the Jews are still his chosen people because of his promises to Abraham, Isaac, and Jacob. 29For Gods gifts and his call can never be withdrawn. 30Once, you Gentiles were rebels against God, but when the Jews refused his mercy, God was merciful to you instead. 31And now, in the same way, the Jews are the rebels, and Gods mercy has come to you. But someday they,£ too, will share in Gods mercy. 32For God has imprisoned all people in their own disobedience so he could have mercy on everyone.
I take All Israel to mean all of the twelve tribes who obey the laws, have not rejected GOD, and are observant Jews.
Paul was compelled by the Spirit, and testified to the Jews that Jesus is the Christ. But when they opposed him and blasphemed, he shook his garments and said to them, "Your blood be upon your own heads; I am clean. From now on I will go to the Gentiles." Acts 18:5-6