Ex opere operato

227. What is the sacramental character?
1121
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.
228. What is the relationship between the sacraments and faith?
1122-1126
1133
The sacraments not only presuppose faith but with words and ritual elements they nourish, strengthen, and express it. By celebrating the sacraments, the Church professes the faith that comes from the apostles. This explains the origin of the ancient saying, “lex orandi, lex credendi,” that is, the Church believes as she prays.
229. Why are the sacraments efficacious?
1127-1128
1131
The sacraments are efficacious ex opere operato (“by the very fact that the sacramental action is performed”) because it is Christ who acts in the sacraments and communicates the grace they signify. The efficacy of the sacraments does not depend upon the personal holiness of the minister. However, the fruits of the sacraments do depend on the dispositions of the one who receives them.