When asked, What is a sacrament?, some say that they are magic and that the minister, whether evil or good, simply says the right words, and then God does the rest. 

My response to the remark about “magic” is that the sacraments are from Christ, whereas magic is from man. The sacraments bestow God’s grace, which the recipient is free to cooperate with or not. Humans use magic to manipulate the world and the humans it.

Interestingly, the answer above mentioned the minister rather than the recipient of the sacraments.

During the sacramental liturgy, the recipient has to be well-disposed to receive the sacraments. She needs wakening faith, conversion of heart, and adherence to the Father’s will. She must be in a state of baptismal grace to receive the sacraments of Confirmation, the Eucharist, Holy Orders, and Matrimony. Suppose by mortal sin she has lost that grace. In that case, she must regain it by the sacrament of Penance, which requires its own dispositions—she must be genuinely contrite. She must confess each of her grave sins to the best of her knowledge.

As the Church explains:

“The assembly should prepare itself to encounter its Lord and to become “a people well disposed.” The preparation of hearts is the joint work of the Holy Spirit and the assembly, especially of its ministers. The grace of the Holy Spirit seeks to awaken faith, conversion of heart, and adherence to the Father’s will. These dispositions are the precondition both for the reception of other graces conferred in the celebration itself and the fruits of new life which the celebration is intended to produce afterward.”

Catechism of the Catholic Church, 1098

Regarding the minister who does not cooperate with the grace received during his ordination, Augustine says:

“As for the proud minister, he is to be ranked with the devil. Christ’s gift is not thereby profaned: what flows through him keeps its purity, and what passes through him remains clear and reaches the fertile earth.… The spiritual power of the sacrament is indeed comparable to light: those to be enlightened receive it in its purity, and if it should pass through defiled beings, it is not itself defiled.”