One of the more controversial texts in the New Testament, at least as far as the range of interpretations it has generated, is Romans 11:26. The verse reads: 'And in this way all Israel will be saved, as it is written: "The Deliverer will come from Zion, and he will remove ungodliness from Jacob".'
The disputed interpretation concerns the meaning of 'all Israel' in the verse.
There are essentially three interpretations as follows:
1. The first and most common interpretation is that 'all Israel' means that ethnic Israel as a whole (or the vast majority of the Jewish people) will be saved at some point in the future. This view envisages a future conversion of the mass of Jewish people. There is a minority view within this position that the Jews as a nation will be saved in the future, irrespective of turning and accepting Jesus as the Messiah. Yet most people who hold to this position believe in a future conversion of the Jewish people to faith in Christ. This view is common among premillennialists and postmillenialists and was the majority view of the Puritans and also of many commentators on Romans such as Charles Hodge, John Murray, and John Stott.
2. Another view, held by William Hendriksen, Louis Berkhof, Antony Hoekema, R. C. H. Lenski, O. Palmer
Robertson and others, agrees that there is no 'future conversion' of the
Jewish nation in view, but rather 'All Israel' means all elect Jews—the
sum of all the believing remnants down through history. This view points to the fact that there has always been a believing
remnant within ethnic Israel and believes this will continue all through
time. 'All Israel' is therefore the sum total of all the
believing remnants both in New Testament times and right through to the
end of time. This view seems most common among Dutch Reformed
theologians and commentators.
3. A third view agrees with the second view in part, in that it agrees the passage does not point to a
future mass conversion of the Jewish ethnic nation, but differs from the second view in that
it sees in Romans 9-11 a Pauline redefinition of 'Israel' so that 'all Israel'
means all the elect, both Jew and Gentile together. The third view therefore sees 'all Israel' as a reference to all of God's elect people, consisting both of Jews and Gentiles, throughout the ages. This view has been held historically by figures such as St Augustine and John Calvin, and in our day by the Pauline scholar, N. T. Wright.
For a number of reasons, my own view is that the third option is the correct interpretation, although it is definitely a minority view.
For a full discussion and argument why 'All Israel' means all the elect, both Jew and Gentile, I thoroughly recommend the commentaries by Calvin and N. T. Wright on this verse and passage. In addition, I recommend an essay by Lee Irons, "Paul’s Theology of Israel’s Future: A Non-Millennial Interpretation of Romans 11" which can be found here.
Calvin's comments on this verse are worth quoting:
Many understand this of the Jewish people, as though Paul had said, that religion would be restored among them as before: but I extend the word Israel to all the people of God, according to this meaning, - "When all the Gentiles shall come in, the Jews also shall return from their defection to the obedience of faith; and thus shall be completed the salvation of the whole Israel of God, which must be gathered from both; and yet in such a way that the Jews shall obtain the first place, being as it were the first-born in God's family." This interpretation seems to me the most suitable, because Paul intended here to set forth the completion of the kingdom of Christ, which is by no means to be confined to the Jews, but is to include the whole world. The same manner of speaking we find in Gal. vi. 16. The Israel of God is what he calls the Church, gathered alike from Jews and Gentiles." (John Calvin, Commentary on the Epistle of Paul the Apostle to the Romans (translated and edited by John Owen; Grand Rapids, MI, Eerdmans, 1955), p. 437.
My reasons for accepting Calvin's view (and N. T. Wright's) can be summarised as follows:
1. The verse says all Israel will be saved in this way. It does not say and then all Israel will be saved. The future national conversion view requires the verse to mean "and then" but this is not what the Greek means. There is nothing in this verse that points to this as being a future prophecy. The arguments of those who take the second interpretation such as Hendriksen and Robertson also support this, as do the arguments of Calvin and Wright.
2. If the verse does mean that all Israel will be saved in this way this must refer back to what verse 25 says - that a partial hardening has come upon Israel until the full number of the Gentiles comes in. The 'until' here should be viewed as a terminus ad quem and not a terminus a quo. Just as in Psalm 110:1 where we read that Christ must reign 'until' he has put all his enemies under his feet, this does not imply that Christ will cease to reign at that point, so here 'until' does not imply that the hardening will cease when the full number of Gentiles comes in, but rather that the hardening will continue right through to when Christ returns and this world ends.
3. Throughout the Bible, God only has one covenant people. In the Old Testament the covenant people are usually called Israel; in the New Testament the covenant people are usually called the Church, but they are one people - Israel is the Church and the Church is the true Israel. Paul makes this point throughout his writings.
4. Paul's argument in Romans 11 is that believing Jews and believing Gentiles are both branches - natural and grafted - into the ONE olive tree - which is a symbol of Israel or the covenant people. Verse 25 says this process will go on until the full number of Gentiles come into the covenant people and IN THIS WAY all (the true) Israel will be saved. This is entirely in line with Paul's arguments throughout Romans (and similarly in passages such as Ephesians 2:11-20). This view is also in line with Paul's key verse in Romans 9:6 where he begins to flesh out what he has already hinted at in Romans 2, that there is a "true Israel" of which not all ethnic Jews are a part: "For not all those who are descended from Israel truly belong to Israel."
5. One of the main arguments against this view that 'all Israel' means both the Jewish and Gentile elect is that it is hard to believe Paul could use 'Israel' meaning 'ethnic Israel' in verse 25, but in a different way in verse 26. However, this objection does not stand up to scrutiny. Paul clearly uses Israel in two different ways in Romans 9.6 which literally says 'not all Israel are Israel' meaning 'ethnic Israelites' in the first use and 'God's covenant people' in the second use.
These points are made more fully for those who want to probe deeper into these issues in the writings of Hendriksen, Robertson, Hoekema, Calvin, Wright and Irons' essay. Although not all of these scholars agree that 'all Israel' means all elect Jews and Gentiles, they do give reasons to reject the first view that the verse means 'and then [at some future point] all [ethnic] Israel will be saved'. Of the two remaining views, I think it makes most sense in Paul's argument - particularly since he describes this as a mystery - that he is not merely describing the salvation of all elect Jews throughout time - but that in God's purpose both Jews and Gentiles are brought together into God's covenant people (Israel) to bring about the salvation of both.