CATECHISM OF THE CATHOLIC CHURCH
SECOND EDITION

Paragraphs 1582–1586

1582 As in the case of Baptism and Confirmation this share in Christ's office is granted once for all. The sacrament of Holy Orders, like the other two, confers an indelible spiritual character and cannot be repeated or conferred temporarily.
1583 It is true that someone validly ordained can, for grave reasons, be discharged from the obligations and functions linked to ordination, or can be forbidden to exercise them; but he cannot become a layman again in the strict sense, because the character imprinted by ordination is for ever. The vocation and mission received on the day of his ordination mark him permanently.
1584 Since it is ultimately Christ who acts and effects salvation through the ordained minister, the unworthiness of the latter does not prevent Christ from acting. St. Augustine states this forcefully:

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 dear 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.

1585 The grace of the Holy Spirit proper to this sacrament is configuration to Christ as Priest, Teacher, and Pastor, of whom the ordained is made a minister.
1586 For the bishop, this is first of all a grace of strength ("the governing spirit": Prayer of Episcopal Consecration in the Latin rite): the grace to guide and defend his Church with strength and prudence as a father and pastor, with gratuitous love for all and a preferential love for the poor, the sick, and the needy. This grace impels him to proclaim the Gospel to all, to be the model for his flock, to go before it on the way of sanctification by identifying himself in the Eucharist with Christ the priest and victim, not fearing to give his life for his sheep:

Father, you know all hearts.
You have chosen your servant for the office of bishop.
May he be a shepherd to your holy flock,
and a high priest blameless in your sight,
ministering to you night and day;
may he always gain the blessing of your favor
and offer the gifts of your holy Church.
Through the Spirit who gives the grace of high priesthood
grant him the power
to forgive sins as you have commanded
to assign ministries as you have decreed
and to loose from every bond by the authority which you
gave to your apostles. May he be pleasing to you by his gentleness and purity of heart,
presenting a fragrant offering to you,
through Jesus Christ, your Son. . . .