"The Lord's Day — as Sunday was called from Apostolic times — has always been accorded special attention in the history of the Church because of its close connection with the very core of the Christian mystery. In fact, in the weekly reckoning of time Sunday recalls the day of Christ's Resurrection. It is Easter which returns week by week, celebrating Christ's victory over sin and death, the fulfilment in him of the first creation and the dawn of "the new creation" (cf. 2 Cor 5:17). It is the day which recalls in grateful adoration the world's first day and looks forward in active hope to "the last day", when Christ will come in glory (cf. Acts 1:11; 1 Th 4:13-17) and all things will be made new (cf. Rev 21:5)."
The Lord's Day
Pope John Paul II