1 Thess. 4, 13-18.
But we do not want to keep you, brethren, from those who are asleep, so that you will not be sad like the others who have no hope. For if we believe that Jesus died and rose again, God will also bring with Him those who have fallen asleep through Jesus. For this we say unto you, as the word of the Lord, that we which are alive and remain unto the future of the Lord shall not appear unto them which sleep. For the Lord Himself will come down from heaven with a shout and the voice of the 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 so shall always be with the Lord. So comfort yourselves with these words among yourselves.
This piece is written by St. Paul for the comfort of Christians who were anxious about how the resurrection of the dead would take place, whether they would all rise together; item, whether those who would experience the last day would come to Christ sooner than the others etc. To this
St. Paul tells them how Christ will take together all his believers who have ever lived etc. But you will find this epistle abundantly interpreted in the interpretations of some epistles, especially those that have gone out, so you can look for them there.