This is in contrast to the more popular premillennial view, which holds that the Second Advent precedes the millennial kingdom, which will be ruled by Christ on earth.
The amillennialism view has a timeline similar to the postmillennial view, namely that the millennial kingdom comes first, followed by the Second Coming.
The difference between postmillennialism and amillennialism is in the nature of the kingdom.
In amillennialism, it is purely spiritual, and in fact refers to the present church age. There is no expectation of a literal millennial kingdom: that is just a reference to the Spirit filled church and refers to the entire period between the First and Second Advent. The present age will simply end with Second Coming. A general increase in evil and apostasy is expected, culminating with the Second Coming, the general resurrection, the Last Judgment, and new heaven and earth. As far as human history is concerned, things will keep getting worse. Like premillennialism, the overall view is one of pessimism.
Postmillennialism is optimistic about the future. It holds that things will get better, and that the great commission will, in some measure succeed. This will lead (perhaps so gradually that the start cannot be determined—perhaps it has already begun) to the earthy millennial kingdom, ruled by Christ in Heaven. In general, the 1000 year duration is not taken literally. After the "millennium" Christ will return, there will be a general resurrection and final judgment.
Of course, there are many details which have been omitted. The only point I want to make is that postmillennialism is optimistic.
That has been its downfall. How could anyone think things are getting better?
There are three lines of attack to this criticism.
- Things are getting better. Everyone throughout history always thinks they live in the worst of times. So do we. Yet it wasn’t that long ago that you could be killed for having an English translation of the Bible. Calvin's Geneva, it pains me to say, was not a safe place for dissenters. There are more Christians now than ever before, with vast inroads being made in Asia, Africa, and South America. Are you sure things are getting worse?
- Things are getting worse at the moment, but like the stock market, the long term trend always has a positive slope.
- It is a mistake to look at, or at least to overemphasize human history, for we are limiting God to work within the confines of what we think is possible. The only relevant question is: Does scripture teach that we have reason for optimism? Does it teach that God promises that the great commission will succeed, and that there will be multitudes of believers from all nations? The postmillennialist says that it does, and what we should believe is scripture, not our extrapolation of human history, whose course God can alter in an instant by Holy fiat.
It is scripture, not CNN, from which we should learn eschatology.