The reason premills say that there are unsaved survivors who live on at the return of Christ is their doctrine requires babies to be born and the population on the earth to grow like the sands of the seashore. (Gee wiz sounds like the way it is now) And all those babies grow up to be Christ haters, that Christ is ruling over a humongous number of enemies and these enemies cover the face of the whole earth in number. So the kingdom of God instead of steadily growing larger and filling the whole earth like Christ teaches, shrinks smaller and smaller as the 1000 years reign progresses according to them.
Theses humongous number of satanists then go on to attack the 'camp of the saints' and God sends down fire from heaven to destroy them all...
It sure sounds like the second coming in fiery wrath of Christ, but the premills say he already came back a thousand years beforehand.
Rev 20, the satanic rebellion is destroyed at Christ's return, just like 2 Thessalonians 2 teaches. Not after 1000 years of time after Christ's return, so this reigning with Christ is not on this earth.
The Saints Reign with Christ 1,000 Years
4 And I saw thrones, and they sat on them, and judgment was committed to them. Then
I saw the souls of those who had been beheaded for their witness to Jesus and for the word of God, who had not worshiped the beast or his image, and had not received
his mark on their foreheads or on their hands. And they lived and reigned with Christ for [
a]a thousand years. 5 But the rest of the dead did not live again until the thousand years were finished. This
is the first resurrection. 6 Blessed and holy
is he who has part in the first resurrection. Over such the second death has no power, but they shall be priests of God and of Christ, and shall reign with Him a thousand years.
Satanic Rebellion Crushed
7 Now when the thousand years have expired, Satan will be released from his prison 8 and will go out to deceive the nations which are in the four corners of the earth, Gog and Magog, to gather them together to battle,
whose number is as the sand of the sea. 9 They went up on the breadth of the earth and surrounded the camp of the saints and the beloved city. And fire came down from God out of heaven and devoured them. 10 The devil, who deceived them, was cast into the lake of fire and brimstone where[b] the beast and the false prophet are. And they will be tormented day and night forever and ever.
2 Thess 2 is where Rev 20:9 happens, immediately at Christ's return, not 1000 years after Christ's return
The Great Apostasy
2 Now, brethren, concerning the coming of our Lord Jesus Christ and our gathering together to Him, we ask you, 2 not to be soon shaken in mind or troubled, either by spirit or by word or by letter, as if from us, as though the day of [
a]Christ had come. 3 Let no one deceive you by any means; for
that Day will not come unless the falling away comes first, and the man of [
b]sin is revealed, the son of perdition, 4 who opposes and exalts himself above all that is called God or that is worshiped, so that he sits [
c]as God in the temple of God, showing himself that he is God.
5 Do you not remember that when I was still with you I told you these things? 6 And now you know what is restraining, that he may be revealed in his own time. 7 For the [
d]mystery of lawlessness is already at work; only [
e]He who now restrains
will do so until He is taken out of the way. 8
And then the lawless one will be revealed, whom the Lord will consume with the breath of His mouth and destroy with the brightness of His coming. 9 The coming of the
lawless one is according to the working of Satan, with all power, signs, and lying wonders, 10 and with all unrighteous deception among those who perish, because they did not receive the love of the truth, that they might be saved. 11 And for this reason God will send them strong delusion, that they should believe the lie, 12 that they all may be condemned who did not believe the truth but had pleasure in unrighteousness.