On Sunday, we gather as the Body of Christ to celebrate the Lord’s Day, the day of Christ’s Resurrection:
As “the first day of the week” (Mk 16:2) it recalls the first creation; and as the “eighth day,” which follows the sabbath, it symbolizes the new creation ushered in by the Resurrection of Christ. Thus, it has become for Christians the first of all days and of all feasts. It is the day of the Lord in which he with his Passover fulfilled the spiritual truth of the Jewish Sabbath and proclaimed man’s eternal rest in God. (Compendium of the Catechism of the Catholic Church, no. 452)
The Scriptures tell us that Jesus rose on the first day of the week—the day following the Jewish Sabbath. Shortly after daybreak, the women found the tomb empty and Jesus risen from the dead. Jesus’ death and Resurrection opened for us the doors of salvation. Sharing in Jesus’ death in Baptism, we hope to share in his Resurrection. We become a new creation in Christ. It is that new creation which we celebrate on Sunday:
This is the day the Lord has made; let us rejoice in it and be glad. (Ps 118:24)
Each Sunday is a “little Easter”—a celebration of the central mysteries of our faith.