At the close of the Millennium or the 1000 years in heaven, Christ with His saints and the Holy City will descend from heaven to earth. The wicked dead will then be resurrected and face the final judgement, along with Satan and his angels at the Lake of Fire which will consume them and cleanse the earth of sin forever.
As Christians we know that Jesus is preparing a place in heaven for us, all Christians should agree on that, and He will come again at the Second Coming and take the saints to heaven. A few days before His death, Jesus told His disciples what He was going to do before coming back at the Second Coming:
John 14:1-3
1 Let not your heart be troubled: ye believe in God, believe also in me.
2 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
3 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.
So how will He come, does the scripture tells us? 40 days after His resurrection, Jesus led His disciples to a clearing and a cloud of angels came and Jesus was raised up into the cloud as we see in Acts 1.
Acts 1:6-11
6 When they therefore were come together, they asked of him, saying, Lord, wilt thou at this time restore again the kingdom to Israel?
7 And he said unto them, It is not for you to know the times or the seasons, which the Father hath put in his own power.
8 But ye shall receive power, after that the Holy Ghost is come upon you: and ye shall be witnesses unto me both in Jerusalem, and in all Judaea, and in Samaria, and unto the uttermost part of the earth.
9 And when he had spoken these things, while they beheld, he was taken up; and a cloud received him out of their sight.
10 And while they looked stedfastly toward heaven as he went up, behold, two men stood by them in white apparel;
11 Which also said, Ye men of Galilee, why stand ye gazing up into heaven? this same Jesus, which is taken up from you into heaven, shall so come in like manner as ye have seen him go into heaven.
Jesus ascended literally, bodily, in full view of His disciples and followers. As they watched Him go up, two angels appeared and said He would come back "in like manner" as He went up. Thus Christ's Second Coming will be literal, bodily, and visible to normal human eyes. Paul told the early believers to keep looking for the visible return of Jesus.
Titus 2:13
Looking for that blessed hope, and the glorious appearing of the great God and our Saviour Jesus Christ;
There will be nothing secret about His return. Jesus told them plainly how it would be, and the Second Coming will be incredible.
Matthew 24:25-27
25 Behold, I have told you before.
26 Wherefore if they shall say unto you, Behold, he is in the desert; go not forth: behold, he is in the secret chambers; believe it not.
27 For as the lightning cometh out of the east, and shineth even unto the west; so shall also the coming of the Son of man be.
But Jesus also warned that false messiahs bring false hope would try to fool them:
Matthew 24:4-5
4 And Jesus answered and said unto them, Take heed that no man deceive you.
5 For many shall come in my name, saying, I am Christ; and shall deceive many
But Christ Second Coming cannot fool the faithful who read His word as they are told clearly what they will see and there is nothing secret about it and how Christ will come. Christ's return will be loud and visible to the eyes of "all the tribes of the earth." When He comes and the heavenly trumpet sounds and the billions of angels come in a great cloud, no one will wake up the next day wondering what happened.
Revelation 1:7
'Look, he is coming with the clouds, and every eye will see him, even those who pierced him, and all peoples on earth will mourn because of him. So shall it be! Amen.'
Matthew 24:30-31
30 And then shall appear the sign of the Son of man in heaven: and then shall all the tribes of the earth mourn, and they shall see the Son of man coming in the clouds of heaven with power and great glory
31 And he shall send his angels with a great sound of a trumpet, and they shall gather together his elect from the four winds, from one end of heaven to the other.
Scripture tells us that at the Second Coming, Christ comes with his angels and resurrects the saints and they rise up to the cloud of angels and Christ takes His saints to heaven and the earth is emptied of its inhabitants. Satan is left to wander the earth alone during the Millennium, as at the coming of Christ the wicked are slain and the earth is left empty and desolate for the 1,000 years and we see it in Revelation 20.
Revelation 20:1-3
1And I saw an angel come down from heaven, having the key of the bottomless pit and a great chain in his hand.
2 And he laid hold on the dragon, that old serpent, which is the Devil, and Satan, and bound him a thousand years,
3 And cast him into the bottomless pit, and shut him up, and set a seal upon him, that he should deceive the nations no more, till the thousand years should be fulfilled: and after that he must be loosed a little season.
During the millennium, the thousand-year period of which Revelation 20 shows us, Satan's will be bound or his influence over the earth will be restricted, and Christ will reign with His saints in heaven.
Revelation 20:4
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.
So lets look at what is happening in heaven during those thousand years with Christ..