The following is an excerpt from The MacArthur New Testament Commentary on Romans 11 .

For I do not want you, brethren, to be uninformed of this mystery, lest you be wise in your own estimation, that a partial hardening has happened to Israel until the fulness of the Gentiles has come in; and thus all Israel will be saved. (Romans 11:25–26)

All Israel must be taken to mean just that—the entire nation that survives God’s judgment during the Great Tribulation. The common amillennial view that all Israel refers only to a remnant redeemed during the church age does injustice to the text. Paul’s declaration about all Israel is set in clear contrast to what he has already said about the believing Jewish remnant which the Lord has always preserved for Himself. The fact, for instance, that only some of the branches (unbelieving Jews) were broken off (v. 17), plainly indicates that a remnant of believing Jews—those not broken off—will continually exist while the fulness of the Gentiles is being completed. These are Jews being redeemed who are not part of the spiritual hardening that has come upon Israel because of her rejection of her Messiah (v. 25).

Before all Israel is saved, its unbelieving, ungodly members will be separated out by God’s inerrant hand of judgment. Ezekiel makes that truth vividly clear:

“As I live,” declares the Lord God, “surely with a mighty hand and with an outstretched arm and with wrath poured out, I shall be king over you. And I shall bring you out from the peoples and gather you from the lands where you are scattered, with a mighty hand and with an outstretched arm and with wrath poured out; and I shall bring you into the wilderness of the peoples, and there I shall enter into judgment with you face to face. As I entered into judgment with your fathers in the wilderness of the land of Egypt, so I will enter into judgment with you,” declares the Lord God. “And I shall make you pass under the rod, and I shall bring you into the bond of the covenant; and I shall purge from you the rebels and those who transgress against Me; I shall bring them out of the land where they sojourn, but they will not enter the land of Israel. Thus you will know that I am the Lord.” (Ezek. 20:33–38, emphasis added; cf. Dan. 12:10; Zech. 13:8–9)

Those who hear the preaching of the 144,000 (Rev. 7:1–8; 14:1–5), of other converts (7:9), of the two witnesses (11:3–13), and of the angel (14:6), and thus safely pass under God’s rod of judgment will then comprise all Israel, which—in fulfillment of God’s sovereign and irrevocable promise—will be completely a nation of believers who are ready for the kingdom of the Messiah Jesus.

“Behold, days are coming,” declares the Lord, “when I will make a new covenant with the house of Israel and with the house of Judah, not like the covenant which I made with their fathers in the day I took them by the hand to bring them out of the land of Egypt, My covenant which they broke, although I was a husband to them,” declares the Lord. “But this is the covenant which I will make with the house of Israel after those days,” declares the Lord, “I will put My law within them, and on their heart I will write it; and I will be their God, and they shall be My people. And they shall not teach again, each man his neighbor and each man his brother, saying, ‘Know the Lord,’ for they shall all know Me, from the least of them to the greatest of them,” declares the Lord, “for I will forgive their iniquity, and their sin I will remember no more.” (Jer. 31:31–34; cf. 32:38)

God’s control of history is irrefutable evidence of His sovereignty. And as surely as He cut off unbelieving Israel from His tree of salvation, just as surely will He graft believing Israel back in—a nation completely restored and completely saved.