1 Thess 4:13-14
"But we do not want you to be uninformed, brothers, about those who are asleep, that you may not grieve as others do who have no hope. For since we believe that Jesus died and rose again, even so, through Jesus, God will bring with him those who have fallen asleep."
The Christian hope in the face of death: not absence of sorrow, but sorrow with hope. The foundation: Jesus’ resurrection guarantees the resurrection of those who died in Christ. 'Asleep' (koimomenous) is a Christian metaphor for death—temporary, with a guaranteed awakening.
1 Thess 4:16-17
"For the Lord himself will descend from heaven with a cry of command, with the voice of an archangel, and with the sound of the trumpet of God. And the dead in Christ will rise first. Then we who are alive, who are left, will be caught up together with them in the clouds to meet the Lord in the air."
The parousia: the personal, visible, and audible coming of Christ. The sequence: (1) cry of command; (2) voice of the archangel; (3) trumpet of God; (4) resurrection of the dead in Christ; (5) rapture of the living. 'To meet the Lord in the air' (apantesis)—the technical term for leaving a city to receive a dignitary.