Anthony Hoekema (d. 1988) wrote a helpful critique of dispensational premillennialism in his excellent book, The Bible and the Future. Because I think they are helpful, I’m going to summarize and edit them below. I strongly recommend reading the entire 20 page chapter for the full discussion – along with exegesis and detailed explanation.
1) Dispensationalism fails to do full justice to the basic unity of biblical revelation. …One great difficulty with the dispensational system…is that in it the differences between the various periods of redemptive history seem to outweigh the basic unity of that history. …When one does not do full justice to the unity of God’s redemptive dealings with mankind, and when one makes hard and fast distinctions between the various dispensations, the danger exists that one will fail to recognize the cumulative and permanent advances which mark God’s dealings with his people in New Testament times. …The principle of discontinuity between one dispensation and another overrules and virtually nullifies the principle of progressive revelation.
2) The teaching that God has a separate purpose for Israel and the church is in error. …As a matter of fact, the New Testament itself often interprets expressions relating to Israel in such a way as to apply them to the New Testament church, which includes both Jews and Gentiles (cf. Gal. 3:28-29; 6:15-16, Eph. 2:11-22, Heb. 12:22, 1 Peter 2:9, etc.). …To suggest that God has in mind a separate future for Israel in distinction to the Gentiles is like putting the scaffolding back up after the building has been finished; it is like turning the clock of history back to Old Testament times.
3) The Old Testament does not teach that there will be a future millennial kingdom. When one looks at the chapter and section headings of the New Schofield Bible, one finds that many sections of the Old Testament are interpreted as describing the millennium. However, the Old Testament says nothing about such a millennial reign. Passages commonly interpreted as describing the millennium actually describe the new earth which is the culmination of God’s redemptive work.
4) The Bible does not teach a millennial restoration of the Jews to their land. …To understand these prophecies (about returning to the land) only in terms of a literal fulfillment for Israel in Palestine during the thousand years is to revert back to Jewish nationalism and to fail to see God’s purpose for all his redeemed people. To understand these prophecies, however, as pointing to the new earth and its glorified inhabitants drawn from all tribes, peoples, and tongues ties in these prophecies with the ongoing sweep of New Testament revelation, and makes them richly meaningful to all believers today.
5) Dispensational teaching about the postponement of the kingdom is not supported by Scripture. This teaching must be challenged on at least three points: 1) it is not correct to give the impression that all the Jews of Jesus’ day rejected the kingdom he offered them, 2) the kingdom which Christ offered to the Jews of his day did not involve his ascending an earthly throne, as dispensationalists contend, and 3) if the majority of the Jews had accepted Jesus and his kingdom, how would Christ have gotten to the cross?
6) Dispensational teaching about the parenthesis church is not supported by Scripture. It is not true that the Old Testament never predicts the church. The Old Testament clearly states that the Gentiles will share the blessings of the Jews (Gen. 12:3, 22:28, Ps. 22:27, etc.). The idea of a ‘parenthesis church’ implies a kind of dichotomy in God’s redemptive work, as if he has a separate purpose with Jews and Gentiles. The church was not an afterthought on God’s part, but is the fruit of his eternal purpose which he accomplished in Christ (Eph. 3:8-11).
7) There is no biblical basis for the expectation that people will still be brought to salvation after Christ returns. Dispensationalism teaches that a remnant of Israel and a multitude of Gentiles will come to salvation during the seven-year tribulation. There are clear indications in Scripture, however, that the church (including both Jewish and Gentile believers) will be complete when Christ comes again (1 Cor. 15:23, 1 Thes. 3:12-13, Matt. 24:31, etc.).
8) The millennium of the dispensationalists is not the millennium described in Revelation 20:4-6. Revelation 20:4-6 says nothing about believers who have not died but are still alive when Christ returns (as was argued above). Dispensationalists teach that the millennial age will concern unresurrected people, people who are still living in their natural bodies. But about such people this passage (Rev. 20:4-6) does not breathe a word! Further, Revelation 20:4-6 does not say a word about the Jews, the nation of Israel, the land of Palestine, or Jerusalem.
Anthony Hoekema, The Bible and the Future, chapter 15.