The millennium is one of the most important Christian beliefs about the end of the world. Revelation 20 talks about a period of 1,000 years that Christians generally refer to as "the millennium."
Beginning of the Millennium
Revelation 19:11-21 describes Christ riding out of heaven on a white horse, and He is followed by the armies of heaven, who are also riding white horses (verses 11, 14). Their purpose is to make war with the kings of the earth and their armies (verses 11, 19). Chapter 19 concludes with the enemies of Christ being defeated (verses 20, 21). This symbolic description of the second coming of Christ is immediately followed by the millennium in chapter 20. From this it's evident that Christ's second coming will occur at the beginning of the millennium.
Resurrection of the Righteous
Paul said that "the Lord himself will come down from heaven, with a loud command, with the voice of the archangel and with the trumpet call of God, and the dead in Christ will rise first" (1 Thessalonians 4:16; see also 1 Corinthians 15:51-54). Thus, one of the events to occur at the beginning of the millennium will be the resurrection of the righteous.
Paul then added that "we who are still alive and are left will be caught up together with them [the resurrected saints] in the clouds to meet the Lord in the air. And so we will be with the Lord forever (1 Thessalonians 4:17). This suggests that God's people will be taken to heaven at Christ's second coming, and a statement that Jesus made while He was still on the earth confirms this conclusion. He promised His disciples that "I am going there [heaven] to prepare a place for you. And if I go and prepare a place for you, I will come back [His second coming] and take you to be with me that you also may be where I am" (John 14:2, 3). Jesus is now in heaven (Acts 2:32, 33; Hebrews 9:25), and He promised that at His second coming He would take His people to be with Him, where He is.
Destruction of the Wicked
In 2 Thessalonians 1:9, Paul said that at Christ's second coming the wicked "will be punished with everlasting destruction and shut out from the presence of the Lord." And in the symbolic description of Christ going to war against the kings of the earth and their armies, Revelation 19:18 says that the birds of the air will "eat the flesh of kings, generals, and mighty men, . . . and the flesh of all people, free and slave, great and small." From this it's evident that the wicked will be all be slain at Christ's second coming.
Satan will also be bound during the millennium. Revelation 20:2, 3 says that an angel from heaven "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."
The word "abyss" (sometimes translated "bottomless pit") is from the Greek "abussos." In the Greek version of Genesis 1:2, the word abussos, translated "the deep," is used to describe the pre-Creation condition of the earth—"formless and empty." Revelation simply means that during the millennium Satan will be confined to this desolate earth with no one to tempt.
Revelation says that at Christ's second coming the entire world will be shaken by an earthquake that is so powerful that it will cause the mountains to flatten out and the islands in the sea to disappear (Revelation 6:12— 14; 16:18-20). An earthquake that powerful would collapse all of the skyscrapers in the world's large cities, and it would buckle and destroy all of the world's highways and rail lines. In other words, the earth will be a wreck—"formless and empty."
Some Christians claim that Christ will reign on the earth during the millennium and that the righteous and the wicked will live side-by-side during that time. Adventists disagree with this view for two reasons. First, there isn't the slightest evidence in the New Testament that the righteous and the wicked will live together after Christ's second coming. To the contrary, in His parable of the sheep and the goats, Jesus said that at His second coming the righteous and the wicked will be separated from each other "as a shepherd separates the sheep from the goats" (Matthew 25:32; see also Matthew 13:40-43).
During the Millennium
From what we've already learned, we can draw several conclusions about what will happen during the millennium. Satan will be confined to this earth, where he can spend the time contemplating the terrible mess he's made of things. The bodies of the wicked will be strewn all over the earth.
The righteous, on the other hand, will be in heaven, and Revelation 20 says that they will be "given authority to judge. . . . They will be priests of God and of Christ and will reign with him for a thousand years" (verses 4, 6).
Other verses in the New Testament give us some idea of the nature of this judgment. Paul said that "the saints will judge the world" and "we will judge angels" (1 Corinthians 6:2, 3). Also, Jesus said that "when the Son of Man sits on his glorious throne, you who have followed me will also sit on twelve thrones, judging the twelve tribes of Israel" (Matthew 19:28). In this verse, Jesus combined both the idea of reigning with Him and judging that John spoke about in Revelation 20:4.
After the Millennium
At the end of the millennium, all of the wicked will be resurrected. Revelation 20:5 says, "The rest of the dead [the wicked] did not come to life [were not resurrected] until the thousand years were ended. Verse 7 says that "when the thousand years are over, Satan will be released from his prison." What does this mean? Verse 3 said that Satan was locked in the abyss "to keep him from deceiving the nations anymore until the thousand years were ended." The reason why Satan cannot tempt anyone during the millennium is that, with the righteous in heaven and the wicked dead, there will be no one to tempt. At the close of the millennium, when the wicked are resurrected, there will once again be people to join him in his rebellion against God. This is what we understand Satan's release from prison to mean.
In Revelation 21:2, John says that he saw "the Holy City, the new Jerusalem, coming down out of heaven from God." In Revelation 20:9, John says that he saw the wicked surrounding "the camp of God's people, the city he loves." This city is the New Jerusalem, so the descent of the New Jerusalem to earth will occur simultaneously as the wicked are resurrected and Satan is released from his prison.
In Revelation 20:8, Satan gathers the wicked for battle, and they try to attack the New Jerusalem. At this point, Satan still has not abandoned the purpose he has pursued through out the millennia of earth's history; his purpose is to defeat God and make his rulership of the world permanent.
However, God will interrupt Satan's strategy. John says, "I saw a great white throne and him who was seated on it.... And I saw the dead, great and small, standing before the throne, and the books were opened. ... The dead were judged according to what they had done as recorded in the books" (Revelation 20:11, 12). This scene also reveals the reason why the wicked are raised to life after the millennium—so they can be judged for their evil deeds and condemned once and for all.
Following the judgment of the wicked, they will be destroyed in a lake of fire. However, Peter also describes this lake of fire, and he says that the earth itself will be burned up (2 Peter 3:10-12). Thus, hell is not off in some distant part of the universe, it is not in the center of the earth and it is not happening now. Hell will be the destruction of the entire planet by fire at the end of the millennium.
The lake of fire in Revelation 20:14, 15 is followed immediately by the re-creation of our planet into "a new heaven and a new earth" (Revelation 21:1). Peter used the very same language when, after describing the destruction of the world by fire, he said that there will be "a new heaven and a new earth, the home of righteousness" (2 Peter 3:13). Some people argue that the wicked will burn in hell throughout eternity. However, since hell and the lake of fire that destroys the earth are one and the same, hell cannot last forever if the world is to be re-created as the home of the righteous.
The good news about the millennium is that at its conclusion evil will be completely cleansed from the earth and from the universe. All wars, natural disasters, pain and weeping will be a thing of the past (Revelation 21:4), and God's people will enjoy fellowship with God, Jesus and the angels throughout all eternity.
This article originally appeared in Signs of the Times magazine, July 2011.