The Catechism in Questions & Answers

554. How did the early Apostles treat the promise of Christ’s return?

The promise of Christ’s return played a great role in the preaching of the early Apostles. Next to the sacrificial death and resurrection of Jesus, it was among the most important contents of their faith. They were convinced that Jesus would return in their lifetimes: “Behold, I tell you a mystery: We shall not all sleep, but we shall all be changed” (1 Corinthians 15: 51).
Apostle Paul addressed the congregation in Corinth with the early Christian call of prayer: “Maranatha”, which means “O Lord, come!” (cf. 1 Corinthians 16: 22).
The call to be ready for the return of Christ at all times also comes to expression in the Revelation of Jesus Christ in the words of the Lord: “Behold, I am coming quickly!” (Revelation 3: 11; 22: 7, 12, 20).