And then what happens? We go back to Earth? This concept, with all do respect, makes no sense, and was thought up centuries ago by someone who the church rejected as a false teaching. The 1000 years is not literal. Most of Revelations is no literal, and their numbers are not literal, but mostly symbolic. As far as the question, well, here's what it says in Matthew that I read a few weeks back that explains plain as day that whomever (Christians) is alive when the antichrist comes, will go through that tribulation (as we have been going through the end times since Christ's Resurrectiona and Ascension into heaven), and that for the sake of His elect, he will return before all perish:
Matt. 24:4 And Jesus answerd and said to them: "Take heed that no one deceives you. 5 For many will come in My name, saying, 'I am the Christ,' and will deceive many. 6 Andyou will hear of wars and rumors of wars. See that you are not troubled; for all these things must come to pass, but the end is not yet. 7 For nation will rise against nation and kingdom against kingdom. And there will be famines, pestilences, and earthquakes in various places. 8 All these are the beginning of sorrows.
9 Then they will deliver you up to tribulation and kill you, and you will be hated by all nations for My name's sake. 10 And then many will be offended, will betray one another, and will nate one another. 11 Then many false prophets will rise up and deceive many. 12 And because lawlessness will abound, the love of many will grow cold. 13 But he who endures to the end shall be saved. 14 And this gospel of the kingdom will be preached in all the world as a witness to all the nations and then the end will come.
15 Therefore when you see the 'abomination of desolation,' spoken of by Daniel the prophet, standing in the holy place" (whoever reads, let him understand), 16 "then let those who are in Judea flee to the mountains. 17 Let him whoo is on the housetop not go down to take anything out of his house. 18 And let him who is in the field not go back to get his clothes. 19 But woe to those who are pregnant and to those who are nursing babies in those days! 20 And pray that your flight may not be in winter or on the Sabbath. 21 For then there will be great tribulation, such as has not been since the beginning of th world until this time, no, nor ever shall be. 22 And unless those days were shortened, no flesh would be saved; but for the elect's sake those days will be shortened.
23 "Then if anyone says to you, 'Look here is the Christ!' or 'There!' do not believe it. 24 For false christs and false prophets will rise and show great signs and wonders to decive, if possible, even the elect. 25 See, I have told you beforehand.
26 "Therefore if they say to you, 'Look, He is in the desert!' do not go out; or 'Look, He is in the inner rooms!' do not believe it. 27 For as the lightning comes from the east and flashes to the west, so also will the coming of the Son of Man be. 28 For wherever the carcass is, there the eagles will be gathered together.
29 Immediately after the tribulation of those days the sun will be darkened and the moon will not give its light; the stars will fall from the heaven, and the powers of the heavens will be shaken. 30 Then the sign of the Son of Man will appear in heaven and then all the tribes of the earth will mourn, and they wil see the Son of Man coming on the clouds of heaven with power and great glory. 31 And He will send His angels with a great sound of a trumpet, and they will gather together His elect from the four winds, from one end of the heave to the other."
Reading this, it's plain as day that Christians will be on Earth through the Great Tribulation until Christ's return. Notice the key parts in the verses about His returning for the sake of His elect (lest all would perish), and the fact that it says "immediately after the tribulation of those days....." It doesn't say Christ comes before this to gather His remaining faithful.