Youcat commented through CCC – Question n. 175.

YOUCAT Question n. 175 - Why do the sacraments belong to the Church? Why cannot anyone use them however he wants?    

(Youcat answer) Sacraments are Christ’s gift to his Church. It is her duty to administer them and to protect them from misuse.         

A deepening through CCC       

(CCC 1117) As she has done for the canon of Sacred Scripture and for the doctrine of the faith, the Church, by the power of the Spirit who guides her "into all truth," has gradually recognized this treasure received from Christ and, as the faithful steward of God's mysteries, has determined its "dispensation" (Jn 16:13; cf. Mt 13:52; 1Cor 4:1). Thus the Church has discerned over the centuries that among liturgical celebrations there are seven that are, in the strict sense of the term, sacraments instituted by the Lord.        

Reflecting and meditating 

(Youcat comment) Jesus entrusted his words and signs to specific men, namely, the apostles, who were to hand them on; he did not hand them over to an anonymous crowd. Today we would say: He did not post his inheritance on the Internet for free access but rather registered it under a domain name. Sacraments exist for the Church and through the Church. They are for her, because the Body of Christ, which is the Church, is established, nourished, and perfected through the sacraments. They exist through her, because the sacraments are the power of Christ’s Body, for example in confession, where Christ forgives our sins through the priest.    

(CCC Comment)

(CCC 1118) The sacraments are "of the Church" in the double sense that they are "by her" and "for her." They are "by the Church," for she is the sacrament of Christ's action at work in her through the mission of the Holy Spirit. They are "for the Church" in the sense that "the sacraments make the Church" (St. Augustine, De civ. Dei, 22, 17: PL 41, 779; cf. St. Thomas Aquinas, STh III, 64, 2 ad 3), since they manifest and communicate to men, above all in the Eucharist, the mystery of communion with the God who is love, One in three persons.          

(The next question is: Which sacraments can be received only once in a lifetime?)