Romans 11:26-27 : And so all Israel shall be saved: even as it is written, There shall come out of Zion the Deliverer; he shall turn away ungodliness from Jacob: and this is my covenant unto them, when 1 shall take away their sins. "So" is an adverb of manner; it is here a translation of a Greek word, which means, "in this way (manner), so, under these circumstances." Paul had shown how Gentiles had been grafted into God's favor, and how the Jews, the broken-off branch-es, might also be grafted in again. And so, in this manner, or in this way, shall all Israel be saved. Paul had just said that they would be grafted in again, if they continued not in unbelief. The Holy Spirit did not expect all Jews to turn from their unbelief. Paul did not therefore mean that every person of fleshly Israel would be saved many since then have died in unbelief, and unsaved. And Paul did not say that the time would come when all Jews then living would be saved.
And yet some speak as if that is what he said. When Peter said (Acts 15:11) that the Jews would be saved even as the Gentiles, he did not mean that all of either class would be saved, but that all would be saved as others had been saved--salvation was open to all on the same terms. The Deliverer is Christ Jesus. "Jacob" here stands for the descendants of Jacob. Jesus came to turn away ungodliness from Jacob, and did that for all who accepted him. They were to turn from their ungodliness--their impiety, or irreverence, and he would take away their sins, and that was his covenant with them.