Postmillennialism is the belief that Christ will return after the millennium. Thus, the name “post” (after) millennial (1000). All postmillennialists believe that the current age is the kingdom, while some believe that the millennial phase of the kingdom is present and others hold that it is yet future when the world has been Christianized. Postmillennialists also believe the Church is the agent through which this return to Eden will be mediated by Christ the King from heaven. Most postmillennialist have stressed the preaching of the gospel, resulting in a conversion of most of mankind as the means for Christianization. However, the more recent Reconstructionist version adds to evangelism obedience and faithfulness to biblical law as a condition for victory. Some postmillennialist believe that the conversion of the world will be a very slow and gradual process, taking perhaps thousands of years more. On the other hand, others believe that conversion could happen within a short period of time (about 10 years) as the result of a great revival. Systematic postmillennialism was the last of the three major eschatologies to develop. It was first taught within the church in the seventeenth century.
Ice, Thomas D., "What is Postmillennialism?" (2009). Article Archives. 42.