Try to imagine a world that's always at peace, a world where things are always fair, a world that's ruled by one perfect mind—a utopia. It's hard, isn't it? Especially in a world that's full of continued pain, confusion, and unanswered questions. But one day, you won't have to imagine it, because that world is coming. Over and over again, the Bible speaks of the coming millennium, a time of righteousness when Jesus Himself will rule the earth for a thousand years.
Why do we need a millennium? Why bother with a thousand years on earth instead of just going directly to the eternal state of the new heaven and new earth? One reason is that the millennium is needed to fulfill all the promises God made to Israel about an earthly kingdom (see 2 Samuel 7:16; Psalm 89:3-4).
Another reason is that the millennium will reveal the depths of man's sinful, rebellious nature. Revelation 20 tells us that Satan will be removed during this time, bound in a temporary place of incarceration (see vv. 1-3). But even though he'll be out of the picture, some people will still choose to rebel against the Messiah and His reign. And when Satan is released, he will gather all those people for one final rebellion. It will all go to show that man has a corrupt nature.
But the millennium is also needed to redeem creation from the curse of Genesis 3 and from the judgment God will level against the world during the tribulation period. Basically, God will renovate the earth and restore its beauty. According to Scripture, the animal kingdom will be tamed (see Isaiah 11:6-8). The terrain will be restored, and the entire biosphere of the earth will be lush (see Isaiah 35:1-2, 6-7). Disabilities will be healed (see Isaiah 35:5-6), and there will be increased longevity and health (see Isaiah 65:20). On top of all that, there will be worldwide peace (see Isaiah 2:4). Paradise will be regained.
The millennium will be God's answer to all the prayers of all the saints throughout the centuries: "Your kingdom come. Your will be done on earth as it is in heaven" (Matthew 6:10). To be able to look forward to a kingdom age that will last a thousand years is an incredible hope you have as a believer in Christ. But it doesn't give you permission to check out.
This knowledge of the coming millennium should motivate you to be watchful in the way you live right now. Keep in mind that man may rule presently, but not ultimately. So invest in the eternal kingdom that's coming. As Jesus said, "Seek first the kingdom of God and His righteousness, and all these things shall be added to you" (Matthew 6:33). In other words, invest in things that matter to God. Pursuing a life under the dominion of King Jesus means staying involved in this world while also living for the next one.