The only place we read about the Blessed Millenium is in Rev 20.
Let us do a verse by verse analysis to find where this millennium will be.
Verse 4 : And I saw thrones, and they sat upon them, and judgment was given unto them: and I saw the souls of them that were beheaded for the witness of Jesus, and for the word of God, and which had not worshipped the beast, neither his image, neither had received his mark upon their foreheads, or in their hands; and they lived and reigned with Christ a thousand years.
Verse 4 tells us that the righteous will reign with Christ for 1000 years.
Verse 5: But the rest of the dead lived not again until the thousand years were finished. This is the first resurrection.
Verse 5 tells us that those who take part in the first resurrection will be the ones who reign with Jesus. Also it tells us that the wicked will be dead during the 1000 years.
verse 6: Blessed and holy is he that hath part in the first resurrection: on such the second death hath no power, but they shall be priests of God and of Christ, and shall reign with him a thousand years.
Verse 6 tells us that there will be a second death to the wicked. But the righteous who took part in first resurrection will reign with Jesus.
Verse 7-9,14: And when the thousand years are expired, Satan shall be loosed out of his prison, And shall go out to deceive the nations which are in the four quarters of the earth, Gog, and Magog, to gather them together to battle: the number of whom is as the sand of the sea. And they went up on the breadth of the earth, and compassed the camp of the saints about, and the beloved city: and fire came down from God out of heaven, and devoured them. And death and hell were cast into the lake of fire. This is the second death.
At the end of 1000 years there is a second resurrection where the wicked are resurrected to be punished with fire and the fire from heaven devours them. And this is called the second death.
So there are 2 deaths and 2 resurrections.
First death: For both Righteous and Wicked.
First Resurrection: Only for righteous
Second Resurrection: For the Wicked
Second Death: For the wicked.
To understand where the millennium will be we need to read 1 Thes 5: 16,17
For the Lord himself shall descend from heaven with a shout, with the voice of the archangel, and with the trump of God: and the dead in Christ shall rise first: Then we which are alive and remain shall be caught up together with them in the clouds, to meet the Lord in the air: and so shall we ever be with the Lord.
Those who take part in first resurrection and those who are transformed alive will be caught up together with Jesus in the clouds and will be ever with the Lord.
The millennium will be in Heaven.
John 14:2,3 In my Father’s house are many mansions: if it were not so, I would have told you. I go to prepare a place for you. And if I go and prepare a place for you, I will come again, and receive you unto myself; that where I am, there ye may be also.
When the saints are in heaven the earth will be desolate without any living creature except Satan.
Rev 20: 5 But the rest of the dead lived not again until the thousand years were finished. This is the first resurrection. 7And when the thousand years are expired, Satan shall be loosed out of his prison,
“I beheld the earth, and lo, it was without form and void; and the heavens, and they had no light. I beheld the mountains, and lo, they trembled, and all the hills moved lightly. I beheld, and lo, there was no man, and all the birds of the heavens were fled. I beheld, and lo, the fruitful place was a wilderness, and all the cities thereof were broken down at the presence of the Lord, and by his fierce anger” (Jeremiah 4:23 -26)
This “great day of the Lord” will come “as a destruction from the Almighty” (Joel 1:15). “And the slain of the Lord shall be at that day from one end of the earth even to the other end of the earth: they shall not be lamented, neither gathered, nor buried; they shall be as dung upon the ground” (Jeremiah 25:33).
At the end of 1000 years the new Jerusalem descend from heaven along with the saints
Rev 21: 2 And I John saw the holy city, new Jerusalem, coming down from God out of heaven, prepared as a bride adorned for her husband.
It is this city after descending Satan tried to conquer
Rev 20:9 And they went up on the breadth of the earth, and compassed the camp of the saints about, and the beloved city: and fire came down from God out of heaven, and devoured them
Conclusion: The millennium will be in heaven but after 1000 years we will come back to the ‘New Earth”