Paul explains the Rapture in detail in 1Thessalonians 4:13-19.

v.13 “ But I do not want you to be ignorant, brethren, concerning those who have fallen asleep, lest you sorrow as others who have no hope.”

The Rapture is something important for us to know. Christians know they will see their loved ones again in heaven. Therefore they do not fall apart like those who have no hope of ever seeing their loved ones again. We miss those who have died, but have joy in knowing the separation is only temporary.

v.14 “ For if we believe that Jesus died and rose again, even so God will bring with Him those who sleep in Jesus.”

The souls of Christians in heaven will return with Jesus when He returns to get His bride at the Rapture.

v.15 “ 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.”

This teaching is not an idea of Paul’s, but is a mystery that God revealed to him. The bodies of the souls who return from heaven with Jesus will be raised and transformed and joined with their soul before Christians who are still alive on earth will be transformed.

v.16 “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:”

Christ, Himself, will descend from heaven.
With a shout – a military word commanding an action (like “rise you dead bodies”, like “Lazarus come out”)
With the voice of the archangel – perhaps with further commands or instructions.
With the trump of God. The trumpet was used to call all Israel together.
The dead in Christ will rise first. Transformed bodies caught up to Jesus and joined to the soul prior to the transformation of the living saints.

v.17 “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.”

The bodies of living believers on earth will be transformed and they will be meet Christ in the clouds of the air and be with Him forever. The feet of Christ do not touch the earth, which now is Satan’s realm, until Christ comes to destroy Satan and establish His own kingdom of righteousness.

v.18 “Wherefore comfort one another with these words.”

The Rapture is a great source of comfort for Christians as we are assured of seeing our loved ones again. Therefore Christians do not BURY their dead. You only bury what you don’t want to see again. We instead PLANT our dead because the seed you plant you plan on seeing again and in an even more glorious condition than when you planted it.

Another reference to the Rapture is found in 1Corinthians 15:51-53.

“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. For this corruptible must put on incorruption, and this mortal [must] put on immortality.”

Paul tells us that this teaching was a mystery in the past. A mystery is something unknown except by divine revelation. The Old Testament prophets sometimes puzzled over their own prophesies, but Peter says (1Peter 1:10-12) that the reason they did not understand the prophesies God gave them was because the prophesies were for a later day, the days of Peter, whom Jesus had said would be used to start the Church dispensation as we read in Acts chapter two. Since it is the Church that will be caught up at the Rapture and the Church was a mystery until the day of Pentecost, any reference to the Rapture before that time would necessarily be hard to understand.

God clarified this mystery to Paul and tells the Corinthians plainly that the planted body of every dead Christian will be raised and joined to their soul and then living Christians will be transformed and caught up to take part in this airlift to heaven in their new glorified bodies. In a split second at the sound of the trumpet, the corruptible will be changed to incorruption and mortal changed to immortal.”