Day 151: The Seven Sacraments

Jesus' words and actions during his hidden life and public ministry were already salvific, for they anticipated the power of his Paschal mystery. They announced and prepared what he was going to give the Church when all was accomplished. the mysteries of Christ's life are the foundations of what he would henceforth dispense in the sacraments through the ministers of his Church, for "what was visible in our Savior has passed over into his mysteries." CCC 1115

In today's reading, the Catechism teaches that "the whole liturgical life of the Church revolves around the Eucharistic sacrifice and the sacraments" in a sort of introduction (CCC 1113). The Catechism Compendium summarizes this:

The sacraments, instituted by Christ and entrusted to the Church, are efficacious signs of grace perceptible to the senses. Through them, divine life is bestowed upon us. There are seven sacraments: Baptism, Confirmation, Holy Eucharist, Penance, Anointing of the Sick, Holy Orders, and Matrimony. (#224)

It's fitting that the number of sacraments is seven, as in Scripture, that number signifies completion since they present Christ to us throughout our lives. This is most especially seen in the Eucharist. As the Catechism Companion, Vol II notes:

When we participate in the sacraments, we are not just remembering. The sacraments "are actions of the Holy Spirit at work in his Body, the Church (CCC 1116)... The ordained priesthood guarantees that it really is Christ who acts in the sacraments through the Holy Spirit for the Church (CCC 1120)... The seven sacraments manifest the love of God for man. (pp. 66-67) 

Finally, three of these sacraments leave a permanent mark upon our souls on reception, which is why they can only be received once. The Compendium notes:

It is a spiritual “seal” bestowed by the sacraments of Baptism, Confirmation, and Holy Orders. It is a promise and guarantee of divine protection. By virtue of this seal the Christian is configured to Christ, participates in a variety of ways in his priesthood, and takes his part in the Church according to different states and functions. He is, therefore, set apart for divine worship and the service of the Church. Because this character is indelible the sacraments that impress it on the soul are received only once in life. (#227)