What about Medieval Eschatology? There is not much to say about Medieval Eschatology, except to say that a form of Augustinian eschatology was prevalent. Essentially, the institutional Roman Catholic Church was closely linked to the kingdom of God. We would call this Ecclesiocracy. The Church was at the center of all of society. The Church and the Kingdom were one. The Church was not at the center of the kingdom, but it was the kingdom. It had little concern about “interacting with society and culture.” It was basically what we would call today Amillennialism. It teaches that the kingdom of God is a spiritual kingdom, not interested in transforming culture and civilization.
On October 31, 1517, Luther nailed the ninety-five thesis on the Church door of Wittenberg. That marked the beginning of a new era in Church History. In very general terms, the Reformation reformed the abuses of the Church and once they realized that there would be no change, the Reformers took a path of their own. In those days the Church persecuted those who disagreed with her. Things have changed quite a bit in the last 400 years.
Also, the Reformation provided a better understanding of the doctrine of salvation. Both Calvin and Luther believed strongly that salvation was first and foremost the work of God in our lives; God saves and He alone (Sola Deo Gloria).
But in the area of eschatology, the Reformers spent little time developing their millennium views. To the extent that they dealt with eschatology, the Reformers were in general agreements with Augustine. They all agreed that Premillennialism was wrong. But they did not develop much their view of eschatology. How about Luther and Calvin? Were they in agreement on every matter of eschatology? Though they did not write books on eschatology, they did have their opinions. Luther, for example, was very pessimistic about the future of the church. He believed this in large part because of the corruptions of the Catholic Church. Luther did not believe that the Christian had a duty to have dominion over all things. Calvin, on the other hand, differed with Luther. According to Keith Mathison, “Calvin encourages us to have a zeal for daily progress, but he cautions us that the final and full realization of the kingdom of Christ awaits the Second Coming.” Calvin certainly set the precedent for what we call today Postmillennialism.
And we know this because his followers were the Puritans. The Puritans began to develop what it means to have an optimistic eschatology; a hopeful view of history under Christian influence. So what you have in the beginning of the 18th century all the way to the founding of Princeton Seminary is an overwhelming Postmillennial position among Reformed and non-Reformed Scholars.
Now we come to the 21st century and much has changed. As we all know “The Left Behind Series” theology, which is the theology of Pre-Tribulational Premillenialism is the most prominent eschatology of our day.
In closing, what are some reasons Postmillennialism declined in the 20th century:
a) In the twentieth century there was the rapid growth of liberal theology. It undermined supernatural assumptions. For Postmillennialism, there was a strong reliance on the supernatural power of God to bring about a godly society. With the rise of liberal theology, there was a decline of postmillennial thought.
b) Secondly, the social gospel became very pervasive. Instead of bringing the gospel to sinners, people treated the gospel as equivalent to the welfare system. There was little emphasis on Biblical truth and gospel from the pulpits. This led to a decline of postmillennial thought.
c) Finally, Postmillennialism declined as a result of the growing pessimistic trends in evangelical preaching. One early preacher said: ‘if the ship is sinking, why polish the brass.” That mentality became a part of the evangelical world and naturally postmillennial thought declined.
This is a brief survey of eschatology throughout church history. Next week, we will look at the Biblical Arguments for Postmillennialism and we will see that when we allow the Bible to interpret our future instead of the newspaper, Postmillennialism will become once again the prevailing eschatological view of the church and Christians can be encouraged by the promises of God that the gospel will prevail in time and in history. Amen.
 Quoted in Mathison, pg. 34.
 Postmillennialism: An Eschatology of Hope, pg. 40.
 Mainly taken from the writings of my former professor Keith Mathison at RTS; An Eschatology of Hope, pg. 48.