Romans 11:5 “Even so then at this present time also there is a remnant according to the election of grace.”
11-25 Paul uses the analogy of olive trees. I thought he was speaking of salvation. The cultivated tree is Israel and the wild the Gentiles. The wild could be saved by being grafted in while some cultivated branches were cut off. But it appears he was speaking of the knowledge of salvation. It came first to Israel, but some of them didn’t believe or were cut off. Gentiles can now hear the gospel or be grafted in. Those who accept salvation continue to grow, those who do not are cut off.
25 “…blindness in part is happened to Israel, until the fulness of the Gentiles be come in”
God says He will save Israel during or as a result of their last week spoken of by Daniel.
26-32 Language is difficult. Appears to say all Israel will be redeemed even though they rejected Christ. Perhaps he speaks of those that remain at the end of the final week. I don’t see how any Jew left standing at the end of the Great Tribulation could continue to deny Christ. From what the commentary says, I believe this to be the case. Again, you have to look at Paul’s present narrative, his current point of view. He has been speaking of the difference between Jews and Gentiles as groups. Jews had the knowledge of God and salvation, but many failed to believe. As a nation, they rejected Christ although many received Him. The Gentiles have now gained access to God and the gospel. While we are in the Church Age, awaiting the fullness of the Gentiles to arrive, many of both Jew and Gentile accept Christ and become part of the family of God. Once that is complete, a time will arrive when God redeems the Jews as a nation. The nation as a whole group will recognize Christ, and God will have completed His promise to Abraham. This does not conflict with salvation by grace as it will be by grace that the Jewish nation will accept Christ in that day. They will all finally see Christ for who He is and accept Him as Messiah. I guess we confuse any mention of the Jewish nation with all Jews of all time. That is not the case. As mentioned earlier, those last seven years will bring the Jews back to God to complete the covenant.
I hope you enjoy reading and studying His word. May it accomplish what He desires. Please feel free to comment or post questions. Thanks for reading!