While dispensationalists will concede that this is God’s purpose for the present age, they say Israel’s distinct role resurfaces again after the Rapture when the Gentile church is removed from the earth. This dual redemptive purpose then carries on throughout the millennial age after Christ comes back. If true, this means that it is Christ’s purpose to make the two peoples one is only temporary. God intends to divide Israel (ethnic Jews) again from the Gentiles after the resurrection (1 Thessalonians 4:13-5:11).
Of course, this makes no sense whatsoever. In fact, such a view forces us to see the future millennial age as something completely distinct from Christ’s redemptive purpose under the New Covenant. On these terms, the as-yet future millennium marks a return to Old Testament types and shadows and ignores the fact that the reality is Christ. This not only means that redemptive history takes a giant U-turn after Christ comes back, amounting to a return to the types and shadows which preceded the coming of the Messiah, but it completely ignores the very thing Christ came to do–make the two peoples one by removing all ethnic divisions which previously divided believers! The progress of redemption takes us from promise (types and shadows) to fulfillment (anti-types), not from promise, to temporary (or transitional) fulfillment, and then finally back to the types and shadows.
This is why a Christ-centered hermeneutic changes everything and why this hermeneutic lies at the heart of the differences between Reformed amillennialism and dispensationalism. As Bob Strimple (the former president of Westminster Seminary California, and now professor emeritus of systematic theology) points out in a lecture he often gives on this very topic, there are a number of reasons why Israel’s role in the Old Testament was preparatory to the coming Christ, and can therefore cannot serve as the hermeneutical center of Scripture. The fact is that Christ comes to fulfill (literally) all of the Old Testament promises, not to temporarily put them aside, only to return to them in a future millennium. Strimple bases his view that Christ is the true Israel on the following biblical arguments:
1). Isaiah’s servant songs have a double referent that has long baffled Jewish commentators. On the one hand, they refer to Israel, God’s chosen one and servant (41:8-9; 44:1-2, 21; 45:4; 49:3). On the other, they seem also to refer to some individual (42:1-4). These prophesies are interpreted by the New Testament as referring to Christ (Matthew 8:17 and Acts 8:30-35)
2). Matthew sees a double referent in Hosea 11:1, ("Out of Egypt I called my son")
3). Paul identifies Christ, not physical Israel, as Abraham’s seed (Galatians 3:16). Galatians 3:7 and Romans 4:11, 16, moreover, identify the church as Abraham’s offspring.
4). Henceforth, we are in Christ the true Israel: Galatians 3:26-29, Romans 2:28-29, and Philippians 3:3.
5). The Old Covenant is obsolete, having been superseded by the New: Hebrews 8:8-12 identifies the new covenant with Israel (Jeremiah 31:33-34) with the covenant instituted by Christ with the church. Most importantly, Hebrews 8:13 declares the old covenant obsolete and passing away. This makes impossible the dispensational view of Ezekiel 40-48 as a reinstitution of temple sacrifice.
6). The upshot is that the Old Testament did not see how its own prophesies were to be fulfilled - indeed, it could not prior to Christ. The New Testament authors were able to interpret the Old Testament in the light of His coming of the new covenant that He instituted. So should we.