In the late 17th century, the Unitarian Daniel Whitby (1638-1726) developed a new alternative to both Premillennialism and Amillennialism: Postmillennialism. Just as the name suggests, Postmillennialism is the belief that Jesus will return after the thousand years of Revelation 20. In this scheme, the Millennium, whether literal or figurative for a long period, is a golden age where Christianity has conquered the unbelieving world. During this time, most, if not all people will become saved and Biblical values will flourish. This will so move Jesus that he will return, resurrect the dead all at once, and inaugurate the Eternal State. The Millennial Kingdom is one brought about by the efforts of man instead of by the Messiah upon his return. Postmillennialism is a version of Amillennialism in that it too denies the literal reign of Jesus upon the earth during the thousand years.
There are differing opinions among postmillennialists as to both the nature and extent of the positive changes that must occur. Among conservative postmillennialists, the more important emphasis is placed on the going forth of the Gospel and those saved by hearing it. Many of them also include advances in science, medicine, and human governments in contributing to the improvement of the present age. Another point of disagreement is on how many people will become saved during this golden age. The majority opinion has been that a great many will be saved, without being more specific. While fewer in number, influential postmillennialists, such as B.B. Warfield and Heinrich A.W. Meyer, have argued that every single person alive will become a believer before Jesus returns.
On the key points in Revelation 20, Kenneth Gentry summarized his postmillennial beliefs:
This binding does not result in the total inactivity of Satan; rather it restrains his power by Christ’s superior might…In Revelation 20:4-6 we see the positive implications of Christ’s Kingdom. While Satan is bound, Christ rules and His redeemed people participate with Him in that rule (Rev. 20:4). These participants include both the quick and the dead: the martyred saints in heaven (“those who had been beheaded because of the testimony of Jesus and because of the word of God”) and the persevering saints on earth (“and those who [Gk: oitines] had not worshiped the beast”) (NASB). Christ’s kingdom rule involves all those who suffer for Him and enter heaven above, as well as those who live for Him during their earthly sojourn.
The focus of this series is not on refuting positions in conflict with Premillennialism. Therefore, only some general remarks are provided. First, to claim that the binding of Satan means that his power has merely been limited is unconvincing. The picture painted by Revelation 20:1-3 is of an angel wrapping a great chain around the ancient serpent, casting him into the abyss and sealing it over him (cf. Luke 8:31). This is the outright imprisonment of Satan, not merely a stifling of his influence as he roams free. The purpose of the Devil’s confinement is so that he can no longer gain access to the nations to deceive them (Rev. 20:3). Surely Satan is not restricted from doing so in the present age (e.g. John 14:30; 2 Cor. 4:4; 1 Pet. 5:8). The same criticisms made on the amillennial interpretation of the binding apply here as well.
Note that the reign of the saints with Christ is defined as suffering and living for him. To reign is to have great authority akin to a sovereign. The actual meaning of the word is antithetical to what the postmillennialist would have us believe. Revelation 20:4-6 is clear in teaching that the saints rule with Christ after they are brought to life. The reign does not include those in heaven, a location the passage makes no mention of. Indeed, the apostle previously wrote that the reign of the saints will take place upon the earth (Rev. 5:10).
Over the centuries it should be expected that broader eschatological beliefs would become more specific and systematized, complete with variations according to different interpretations. It is quite another matter to posit an entirely new doctrine on the Millennium over 1500 years after the close of the Canon. It is fair for the postmillennialist to find some agreement in Augustine’s Amillennialism. However, the expectation that the world will become progressively better before the return of Jesus is the opposite of what the early church held to. According to Lactantius, as the end of the world approaches the condition of human affairs must undergo a change, and through the prevalence of wickedness become worse; so that now these times of ours, in which iniquity and impiety have increased even to the highest degree, may be judged happy and almost golden in comparison of that incurable evil.
Lactantius, and the early Christian leaders he represents, have a great deal of support in the overall thrust of Scripture. The kingdoms of fallen man will continue until they are suddenly crushed and replaced by the Messiah’s kingdom at his coming (Dan. 2:44-45). The sons of the evil one are to remain among the sons of the kingdom throughout the present age. Only when it ends will those who commit lawlessness be removed (Matt. 13:24-30, 36-43). Just before the coming of Christ on the clouds, there will be a period of tribulation and then great tribulation such as has not occurred since the beginning of the world (Matt. 24:4-30; cf. Rev. 1:7). A litany of sins will continue to be practiced until the Second Coming (2 Tim. 3:1-13; cf. 2 Tim. 4:3-4). In the later times some will fall away from the faith, turning to deceitful spirits, and the doctrines of demons (1 Tim. 4:1). Before the day of the Lord can come, there must first be an apostasy and the man of lawlessness revealed (2 Thess. 2:1-4).
Paul does not paint the future with rose–colour: he is no smooth–tongued prophet of a golden age, into which this dull earth may be imagined to be glowing. There are sanguine brethren who are looking forward to everything growing better and better and better, until, at last, this present age ripens into a millennium. They will not be able to sustain their hopes, for Scripture gives them no solid basis to rest upon. We who believe that there will be no millennial reign without the King, and who expect no rule of righteousness except from the appearing of the righteous Lord, are nearer the mark. Apart from the second Advent of our Lord, the world is more likely to sink into a pandemonium than to rise into a millennium. A divine interposition seems to me the hope set before us in Scripture, and, indeed, to be the only hope adequate to the occasion.
When the normal meaning of Scripture is ignored, it is often due to some outside influence upon its readers. Postmillennialism was born out of the historical climate at the end of the Renaissance. There was a general consensus that the world was improving through human efforts. This impression not only guided Whitby in formulating his eschatology, but lent to its adoption by others. During the 18th century Great Awakening in the United States, Postmillennialism naturally increased in popularity. Jonathan Edwards deserves much credit for shaping the mass revival and for being the most erudite postmillennial theologian. Postmillennialism’s popularity historically rises and falls along with positive and negative world events. If there is a long period of peace and revival then Postmillennialism becomes easy to embrace. While if there is a world war or an increase in the persecution of Christians then Postmillennialism quickly loses favor. No matter what view of the Millennium one holds to, its veracity must be determined by what Scripture says, and not on the current perception of the world.
HE WILL COME FIRST
All three major views on the Millennium are held today. Evangelicals are typically premillennial while Roman Catholics and mainline Protestants are typically amillennial. A minority of mainline Protestants and evangelicals are postmillennial. The overall thinking of this author echoes the words of Charles Spurgeon:
If I read the word aright, and it is honest to admit that there is much room for difference of opinion here, the day will come, when the Lord Jesus will descend from heaven with a shout, with the trump of the archangel and the voice of God. Some think that this descent of the Lord will be post-millennial—that is, after the thousand years of his reign. I cannot think so. I conceive that the advent will be pre-millennial— that He will come first; and then will come the millennium as the result of his personal reign upon earth.
 C. Marvin Pate, Reading Revelation: A Comparison of Four Interpretive Translations of the Apocalypse (Grand Rapids, MI: Kregel Academic, 2009), 8.
 Kenneth Gentry, “The Meaning of the “Millennium”” The Chalcedon Foundation, accessed August 11, 2016, http://chalcedon.edu/faith-for-all-of-life/the-eschatology-of-victory/the-meaning-of-the-millennium/
 Alexander Roberts, James Donaldson and Arthur Cleveland Coxe, eds., the Ante-Nicene Fathers Volume VII – Fathers of the Third and Fourth Century, 212. Lactantius, the Divine Institutes, bk. VII, ch. XV.
 Charles H. Spurgeon, “The Form of Godliness Without the Power,” Metropolitan Tabernacle Pulpit 35 (1889): 301.
 Charles H. Spurgeon, “Justification and Glory,” Metropolitan Tabernacle Pulpit 11 (1865): 249.