The Church celebrates the mystery of her Lord “until he comes,” when God will be “everything to everyone.” Since the apostolic age the liturgy has been drawn toward its goal by the Spirit’s groaning in the Church: Marana tha! The liturgy thus shares in Jesus’ desire: “I have earnestly desired to eat this Passover with you . . . until it is fulfilled in the kingdom of God.” In the sacraments of Christ the Church already receives the guarantee of her inheritance and even now shares in everlasting life, while “awaiting our blessed hope, the appearing of the glory of our great God and Savior Christ Jesus.” The “Spirit and the Bride say, ‘Come . . . Come, Lord Jesus!”‘
St. Thomas sums up the various aspects of sacramental signs: “Therefore a sacrament is a sign that commemorates what precedes it – Christ’s Passion; demonstrates what is accomplished in us through Christ’s Passion – grace; and prefigures what that Passion pledges to us – future glory.
From the Catechism of the Catholic Church 1130