A short while ago I wrote a post claiming that Paul doesn’t ever teach that the Gentiles are included in Israel. I said:
Gentiles don’t need to be included in Israel. In fact, the opposite is true; we Gentiles are saved by faith in Christ without being included in Israel. That’s one of the apostle Paul’s big points in Romans and Galatians … Jewish Christians and Gentile Christians are united, not in Israel, but in the promises to Abraham and ultimately in Christ.
The natural counter to this claim is: “What about the allegory of the olive tree in Romans 11? Doesn’t that clearly assume that the Gentiles join Israel?” This question is based on a common assumption that the olive tree in Romans 11:17-24 refers to Israel, and that the image of the Gentiles being “grafted in” to this olive tree (e.g. 11:17) must therefore refer to the Gentiles joining Israel. That is, the olive-tree analogy is commonly read ecclesiologically.
But really, this ecclesiological reading of the olive tree doesn’t work when you start to read the passage carefully. I think that it makes far more sense to read the olive tree theologically (with, of course, implications for both Israel and the Gentiles). That is, the all-important root of the olive tree in Romans 11:17-24 doesn’t stand for Israel, but for God’s promises of salvation (and I think especially his promises to Abraham, who is not only the father of Israel but the father of many nations, see Romans 4).
I’ve just read an article by Nikolaus Walter which makes this point very clearly. Since the article is in German, I thought I’d translate some of the key points for English readers:
When interpreting an allegory, we must always be controlled by the question: What does the author probably want to say in the given context, and what lies beyond his immediate horizon? The main problem for the interpretation of Romans 11:17-24 seems to me to be the question: Who or what is Paul speaking about when he talks about the olive tree with its root, trunk and “sap”; i.e. the olive tree along with the “fatness” which proceeds from the root, which is of course the distinguishing honour of the olive tree and makes it suitable as an allegory of salvation?
In my opinion the olive tree, or the trunk, and particularly the root, “is” not = Israel, despite Jeremiah 11:16 ff. For “Israel” is in fact what has branched out of the olive tree, which currently–by virtue of its non-acceptance of Christ Jesus–is in its greater part excluded from the olive tree (Rom 11:25 b).
If the cultivated olive tree, its root and the fat which flows from it into the branches (or fruits!) (Rom 11:17) is to point concretely at anything, then it points above all to God–to his election and promises and the grace of salvation which flows out from him–but it should not be immediately identified with Israel as a people. Israel, which until now has been that which branches out of the olive tree, has grown on this cultivated olive tree; it has its own history of God and salvation in its past and as its foundation; however it “is” not itself this foundation; the root, the trunk, the fat.
And now they [the Gentiles] are through God’s salvific action in Christ planted not in Israel, but rather they are included in the salvific activity of the God of Israel.
The often-applied sentance Rom 11:18 b does not imply that the Gentile Christians are supported by Israel as their “root”. Rather, what is actually said to the Gentile Christians is that they should not boast with respect to the now-broken-off branches, i.e. with respect to Israel; for even they, the Gentile Christians, “support” not the root, but rather are supported by it (but not by the broken-off branches); i.e. they have not become branches on the olive tree and participated in its “fat” by their own power, but rather they are “supported” by God and his gracious election enacted in Jesus Christ, just as formerly Israel was and also yet again will be.
Walter, Nikolaus. “Zur Interpretation von Römer 9-11.” Zeitschrift für Theologie und Kirche 81 (1984): 172-195.