There are seven sacraments celebrated in the Catholic Church: Baptism, Confirmation, Holy Eucharist, Penance, Anointing of the Sick, Holy Orders, and Matrimony. These 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 (Comp 224).
*capable of producing the desired effect
Celebrated worthily in faith, the sacraments confer the grace that they signify. They are efficacious because in them Christ himself is at work: it is he who baptizes, he who acts in his sacraments in order to communicate the grace that each sacrament signifies... (CCC 1127).
..."the sacrament is not wrought by the righteousness of either the celebrant [i.e. priest] or the recipient [i.e. you], but by the power of God." From the moment that a sacrament is celebrated in accordance with the intention of the Church, the power of Christ and his Spirit acts in and through it, independently of the personal holiness of the minister. Nevertheless, the fruits of the sacraments also depend on the disposition of the one who receives them (CCC 1128).
Check out these links:
Not Magic: On the Fruitful Reception of the Sacraments
Are Sacraments Necessary for Salvation? (video)
These are the Sacraments by Fulten J. Sheen (entire book; read "The Sacraments")
Study the Catechism
#218-250English, Español, Português
|part 2, section 1|
English, Español, Português