Millennialism is the belief in a literal reign of Christ on earth for 1,000 years in the future. The word millennium means “1,000 years”—from mille, the Latin word for “1,000,” and the word annus, Latin for “year.” (M is the Roman numeral for 1,000, it takes 1,000 millimeters to make a meter, 1,000 milliliters to make a liter, etc. A person’s per annum salary is their salary for one year.)
What is often referred to as the “millennial kingdom” is mentioned in Revelation 20:1–7:
“And I saw an angel coming down out of heaven, having the key to the Abyss and holding in his hand a great chain. He seized the dragon, that ancient serpent, who is the devil, or Satan, and bound him for a thousand years. He threw him into the Abyss, and locked and sealed it over him, to keep him from deceiving the nations anymore until the thousand years were ended. After that, he must be set free for a short time.
“I saw thrones on which were seated those who had been given authority to judge. And I saw the souls of those who had been beheaded because of their testimony about Jesus and because of the word of God. They had not worshiped the beast or its image and had not received its mark on their foreheads or their hands. They came to life and reigned with Christ a thousand years. (The rest of the dead did not come to life until the thousand years were ended.) This is the first resurrection. Blessed and holy are those who share in the first resurrection. The second death has no power over them, but they will be priests of God and of Christ and will reign with him for a thousand years.
“When the thousand years are over, Satan will be released from his prison” (emphasis added).
This period of 1,000 years is marked by a binding of Satan and the reign of Jesus Christ. When that period of 1,000 years is over, Satan will be released for a short period for a final period of rebellion before the final end of all things.
Much of Christian eschatology (teaching about the “last things”) is couched in terms of a particular view of the millennial kingdom and of when Christ returns in relation to the inauguration of that kingdom.
The postmillennial position interprets Revelation 20 somewhat figuratively and holds that this binding of Satan takes place through the preaching of the gospel and the advance of the church throughout the world. At some point, the world will become predominantly Christian, recognizing Jesus as Lord. Of course, not every individual will be saved, but the worldwide culture will be dominantly Christian, ushering in a golden age of human existence. This golden age will not be based on humanism but on the people and governments of the world making a conscious effort to order things according to the priorities of God’s Word. Christ, though physically absent, will be reigning through His people, and this “golden age” dominance of Christian culture may last for a literal 1,000 years, or that number may figuratively represent a long period of time. At the end, there will be a rebellion, and Christ will return to earth to quash it. The term postmillennial means that Christ will return at the end of the millennial kingdom.
The amillennial position teaches that there is no literal 1,000-year kingdom. The kingdom of God exists right now as Christ reigns as king in the hearts of His people, the church. Satan is bound now, meaning that he cannot prevent the advance of the gospel and the salvation of the elect, but he is still able to wreak havoc in many other areas. The “1,000 years” cannot be literal because it has already been almost 2,000 years since Christ was on earth. The Church may or may not finally “Christianize” the culture of all nations of the world, but the important thing is that the Church lives according to the priorities of God’s Word and proclaims Jesus as Lord. Christ will return one day to quash all rebellion and inaugurate the new heavens and new earth where there is no opportunity for any sin. The position is amillennial because it denies a literal, visible rule of Christ on earth before the new heavens and new earth, but it certainly does not deny the lordship of Christ or His sovereignty over all areas of life.
The premillennial position teaches that Christ will return to earth to inaugurate the millennial kingdom. Despite the best efforts of Christians to take the gospel to the ends of the earth, the world will never be “Christianized,” and culture will continue to grow worse and worse. However, Christ will come and establish His kingdom visibly on earth, and Satan will be bound—unable to have any impact on world affairs. The governments of the nations of the world will submit to Christ, and there will be a “golden age” of human existence. Truth and justice will be the hallmarks of government instead of the self-centeredness and corruption that is common today. However, because there will still be human beings with fallen natures inhabiting the kingdom, there will still be sin and rebellion. At the end of the literal 1,000-year period, Satan will be loosed, and there will be a final rebellion of humanity against Christ. The Lord will put down the rebellion once and for all and usher in a new heaven and new earth where there is no opportunity for any sin.
Those who are looking forward to a future kingdom of 1,000 years’ duration that begins with the return of Christ (premillennialists) are also often referred to as “millennialists.” The term millennialism was in use before the pre-, a-, and post- prefixes were added to the word. In older literature, the position that might be called “premillennialism” today would simply be called “millennialism.” This is the only position that holds to a literal 1,000-year kingdom inaugurated by Christ and characterized by His visible, earthly reign.