The question probably came from Matthew 24:36-41 NIV:
"No one knows about that day or hour, not even the angels in heaven, nor the Son, but only the Father. As it was in the days of Noah, so it will be at the coming of the Son of Man. For in the days before the flood, people were eating and drinking, marrying and giving in marriage, up to the day Noah entered the ark; and they knew nothing about what would happen until the flood came and took them all away. That is how it will be at the coming of the Son of Man. Two men will be in the field; one will be taken and the other left. Two women will be grinding with a hand mill; one will be taken and the other left."
In this passage which man gets to be with Jesus, the Son of Man, the one in the field or the one taken away. And, which woman will experience Jesus, the taken or the one left? According to this passage, the ones taken away experience God's judgment, and the ones that remain experience the presence of Jesus. Why do I say that? What was Jesus' example here? Noah. Who was taken away according to the illustration of Noah? The wicked. Those who did not care about God. Those who were living as if God did not exist. The one who remained was Noah. He was the one saved. Thus, using Jesus' logic, the ones who remain are the ones saved.
Let's look at another passage, the parable of the weeds. I am not going to write out the whole passage here. You will have to look it up yourself (Matthew 13:24-30, 36-39), but here is part of Jesus' interpretation from Matthew 13:40-43 NIV:
"As the weeds are pulled up and burned in the fire, so it will be at the end of the age. The Son of Man will send out his angels, and they will weed out of his kingdom everything that causes sin and all who do evil. They will throw them into the fiery furnace, where there will be weeping and gnashing of teeth. Then the righteous will shine like the sun in the kingdom of their Father. He who has ears, let him hear."
Again, we must ask, who is taken? All who do evil. Who is left behind? The righteous. This would then seem to be a consistent teaching of Jesus.
But then the question may be asked, "what about 1 Thessalonians 4?" Don't the righteous leave and go to Jesus? First of all , this passage from 1 Thessalonians 4:13-17 focuses on the issue of what happens to the followers of Jesus who are dead. That is Paul's main theme. Now let's read verses 15-17 NIV:
"According to the Lord's own word, we tell you that we who are still alive, who are left till the coming of the Lord, will certainly not precede those who have fallen asleep. For the Lord himself will come down from heaven, with a loud command, with the voice of the archangel and with the trumpet call of God, and the dead in Christ will rise first.
After that, we who are still alive and are left will be caught up together with them in the clouds to meet the Lord in the air. And so we will be with the Lord forever."
Did you see what Paul is describing? The coming of the Lord. There seems to be no apparent difference from the above words of Jesus. What happens then according to Paul? The dead in Christ will rise first; that is the heart of this passage. Paul wants them to know that they too will experience Christ coming. The dead in Christ won't miss out on this joyful and awesome experience. After the dead in Christ rise, then those who are alive will them meet the Lord in the air. The question then must be asked, "Where do they go?" Remember, Paul already told us that this is about the coming of the Lord, right? The dead in Christ along with those who are alive in Christ lead Jesus back to the earth in a triumphal procession.
There is no better illustration of this than Jesus' triumphal entry into Jerusalem as described in John 12. Consider this passage from John 12:12-13 NIV:
The next day the great crowd that had come for the Feast heard that Jesus was on his way to Jerusalem. They took palm branches and went out to meet him, shouting, "Hosanna! Blessed is he who comes in the name of the Lord! Blessed is the king of Israel!"
They went out to meet him and helped lead him in. By the way, this was the way kings or dignitaries were often treated. (That is the meaning behind "prepare the way for the Lord in Isaiah 40:3.) See also the story of David returning to Jerusalem in 2 Samuel 19 or the bringing of the ark to Jerusalem in 2 Chronicles 15. So the dead in Christ and the alive in Christ ascend to Jesus as he comes, they lead him with much joy and celebration back to the earth.
I grasp end time theology lightly, because it is so easy to mix metaphors and/or misinterpret visions. After all, they misinterpreted Jesus all the time. Jesus told them, "Destroy this temple and I will raise it again in three days (John 2:19)." Their response: "It has taken 46 years to build this temple and you are going to raise it up in three days." As John shows, they missed the point. Revelation 19-22 is a powerful vision of the wicked being removed from the earth and the people of God dwelling with God on this new earth. People have their different interpretations of how this happens and when it happens. Maybe 1 Thessalonians 4 and Revelation 21:1-4 (below) are different images of the same event. But, either way, who is ultimately left behind on earth? Who is saved? There is no doubt. The people of God will dwell with God on this new earth.
Then I saw a new heaven and a new earth, for the first heaven and the first earth had passed away, and there was no longer any sea. I saw the Holy City, the new Jerusalem, coming down out of heaven from God, prepared as a bride beautifully dressed for her husband. And I heard a loud voice from the throne saying, "Now the dwelling of God is with men, and he will live with them. They will be his people, and God himself will be with them and be their God. He will wipe every tear from their eyes. There will be no more death or mourning or crying or pain, for the old order of things has passed away."
In the words of Revelation 22:20 NIV, "He who testifies to these things says, "Yes, I am coming soon." Amen. Come, Lord Jesus."