How did you come to conclude that the New Jerusalem appears at the beginning of the millennium? When I read Rev. 20-21, it seems like the order of things are as follows: 2nd coming of Christ, Satan is bound, millennium period, Satan is released/defeated, old heaven and earth pass away (Rev. 20:11), Great White throne judgment, eternity begins with a new heaven and earth, New Jerusalem descends, “it is done” (Rev. 21:6). Am I misunderstanding something?
It’s a common mistake, one I made myself for several years, and if the Bible ended with Rev. 21, there would be little doubt.
But the first hint that told me I was wrong is in Rev. 22:2 where it mentions fruit trees bearing a different fruit each month. That means man is still measuring time, so eternity can not have begun. (Eternity by definition is the absence of time and is the name given to everything that happens after Satan’s final defeat and the Great White Throne judgment.)
Then I discovered a parallel passage in Ezekiel 47:12 that’s obviously Millennial in it’s focus so Rev 22 has to be describing the Millennium. Somewhere along the way John had skipped forward in the sequence and then back tracked.
Then I began noticing other things. The nations will walk be the light of the New Jerusalem, so it’s near the Earth but not on it, and the Kings of the Earth will bring their treasure into it but can’t enter themselves.(Rev. 21:24) Neither can any other sinner, which means there’ll still be natural beings committing sins on Earth. That’s only true during the Millennium. In Rev. 21:1, the phrase “new heaven and new earth” echoes Isaiah 65:17-25, a Millennial passage, and recalls the Lord’s mention of the renewal of all things in Matt. 19:28 when He sits on His glorious throne and the disciples will judge Israel, another Millennial event.
Then I realized that John had taken the things he’d been talking about in Rev. 20, Satan’s temporary confinement and the Resurrection of unbelievers, and carried them to their conclusion while he was on the subject. All of Rev. 20:7-15 is a parenthetical statement describing the resolution of these things.
He then backed up to where he had begun, the Millennium, describing the New Jerusalem, home of the redeemed during the Millennium in Rev. 21, and conditions on Earth, home of Israel and the nations during the same time in Rev.22.