The Folly Of Postmillennialism

Postmillennialism, otherwise known as dominionism, holds that the church will develop a larger and larger degree of influence over world cultures in a "millennium" that might literally last 1,000 years, a trend that culminates with the Second Coming of Christ.  It may posit an optimistic prediction of humanity's practice of Christian ethics, but it is merely an assumed optimism.  The Bible goes beyond simply not predicting that a golden age of Christian influence will or must occur before Christ's return (here, I mean the influence of intelligent, just Christians, not the influence of the shallow anti-intellectuals and anti-moralists identifying as Christians).  It actually states the opposite!

The church is never promised "dominion" over the earth prior to the return of Christ.  Contrarily, the Bible predicts that the church will suffer various persecutions and that the world as a whole will see increasingly destructive natural disasters and pestilences before Christ returns (as is described in much of Matthew 24).  Of course, this does not mean that there cannot be years or even centuries of collective moral progress.  It only means that the Bible teaches that the era before the Second Coming will not end before it is marked by calamities and moral disarray.

Yes, Biblical eschatology does see the church survive these trials and emerge victorious in an ultimate sense, but the Second Coming is never said to be contingent on the church gaining any level of social or political power.  This is not to say that a culture's values have any philosophical basis outside of theism; morality itself cannot exist unless there is a deity in whose nature it is grounded, as conscience and cultural agreement are irrelevant to everything about moral epistemology and metaphysics.

Rather, this means that there is no threshold of church influence (not that members of the church having influence is positive unless they are rationalistic and morally sound to begin with) that serves as a prophetic prerequisite to Christ's return.  Any dominion on the part of the church as a whole is not guaranteed until after the Second Coming, for the church will almost certainly not be free from oppressors until the eternal state.  After all, it is because of Christ's power that the church is promised power in a life to come, not because of social influence.