1 Thessalonians 4:16 (ESV)

16 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.

It will happen on that day! The Lord Jesus descends from heaven as promised (Acts 1:11). With this, an insistent command is given (keleusma is a command from an army officer), the forceful voice of an archangel and the deafening trumpet of God. No one can escape this. It can be compared with God’s imposing presentation on Mount Horeb (Exodus 19:16–19). Exactly as Jesus spoke in his sermon about the Son of Man (Matthew 24:31 with a loud trumpet call).

The dead in Christ (nekroi en Christoi) will rise first. Here one may think of the people who loved Jesus in their lives on earth, and therefore in one way or another stayed connected with their Lord and Saviour. A telling parallel here is 1 Corinthians 15:52 in a moment, in the twinkling of an eye, at the last trumpet. For the trumpet will sound, and the dead will be raised imperishable. They will be raised first. But there will be more who will follow!