This is a big can of worms. There is such a load of manure out there and it needs to be buried and composted where it will do some good. I’m not going to bother listing all the crazy theories, nor addressing them directly.
Jesus Christ will return someday in the future, quite literally. He warned us that it would be impossible to know, or even guess intelligently, based on any current events leading up to that moment. He pointedly said that the Father keeps it a secret from all other beings, including Jesus Himself. But we do have some idea what will take place when He does return.
1 Corinthians 15:51-52 — Behold, I tell you a mystery: We shall not all sleep, but we shall all be changed — in a moment, in the twinkling of an eye, at the last trumpet. For the trumpet will sound, and the dead will be raised incorruptible, and we shall be changed.
1 Thessalonians 4:15-17 — For this we say to you by the word of the Lord, that we who are alive and remain until the coming of the Lord will by no means precede those who are asleep. For the Lord Himself will descend from heaven with a shout, with the voice of an archangel, and with the trumpet of God. And the dead in Christ will rise first. Then we who are alive and remain shall be caught up together with them in the clouds to meet the Lord in the air. And thus we shall always be with the Lord.
2 Peter 3:10 — But the day of the Lord will come as a thief in the night, in which the heavens will pass away with a great noise, and the elements will melt with fervent heat; both the earth and the works that are in it will be burned up.
Paul and Peter were addressing contextual questions from those whom they wrote. We also have the passage in Matthew 24-25 that most Western Christians get all muddled up. And they refuse to understand that the Book of Revelation says darned little about the End Times and a lot about how God operates, particularly in terms of His wrath on sin. There have been, and will be, times of great tribulation, but there will be no Great Tribulation as taught in the Dispensationalist mythology. There will be no preceding clues to His Return.
What will happen when He does return is a grand homecoming in the sky. All of the Elect will rise to meet Him in the air, with the dead rising first from their graves. While we are up there, He will restore Eden. That is, everything mankind has done to Creation since the Fall will be destroyed and forgotten. There is no human accomplishment that matters to God. Only the changes in our souls are eternal. Somewhere during this process, everyone who is not Elect will go to face eternal judgment. Their presence on the earth will be forgotten, too.
Once things have been restored, we will all descend and go about whatever it was God designed us for in the first place. Since all of this is incomprehensible to us, that’s the end of the story — Eternally Happy Ever After.
Further embellishments are obscene.