"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." (1 Thessalonians 4:16)
Paul instructs the Thessalonians to live in order to please God, as indeed they are living, and to do so more and more. The will of God is their sanctification: to avoid sexual immorality, to control their own body in a way that is holy and honourable, not in passionate lust like the pagans who do not know God. This is not merely ethical instruction but theological: the body belongs to God and is to be used in a way consistent with that ownership. They are to love one another, working with their hands, living quietly, so that their daily life may win the respect of outsiders and they will not be dependent on anybody. The combination of interior holiness and exterior industry, of contemplative love and practical labour, is Paul's portrait of the mature Christian.
The Thessalonians have been troubled about those who have died before the Lord's return. Paul addresses this with the oldest eschatological teaching in the New Testament. He does not want them to grieve like those who have no hope. We believe that Jesus died and rose again, and so we believe that God will bring with Jesus those who have fallen asleep in him. 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, those who are still alive will be caught up together with them to meet the Lord in the air. So we will be with the Lord forever. Therefore encourage one another with these words.
The Catechism presents the resurrection of the dead as the article of faith that transforms the Christian understanding of death: those who have died in Christ have not simply ceased to exist but are held in the hands of the God who raises the dead, awaiting the full resurrection at the end (CCC 989).
Brothers and sisters, encourage one another with these words. The resurrection is not a private consolation for the dying. It is the word Paul gives the community for use with one another. Someone near you today is grieving. Someone has lost hope. Give them 1 Thessalonians 4. We believe that Jesus died and rose again. Therefore we believe in those who have fallen asleep in him. We will be with the Lord forever. Encourage one another with these words.
Lord Jesus, you died and rose again, and so we trust that those who have fallen asleep in you are held in God's hands. Comfort those who grieve without hope. Strengthen our own hope in the resurrection. We will be with you forever. Through Christ our Lord. Amen.