THE SACRAMENT OF HOLY ORDERS
1536 Holy Orders is the sacrament through which the mission entrusted by Christ to his apostles continues to be exercised in the Church until the end of time: thus it is the sacrament of apostolic ministry. It includes three degrees: episcopate, presbyterate, and diaconate.
(On the institution and mission of the apostolic ministry by Christ, see above, no. 874 ff. Here only the sacramental means by which this ministry is handed on will be treated.)
I. WHY IS THIS SACRAMENT CALLED "ORDERS"?
1537 The word order in Roman antiquity designated an established civil body, especially a governing body. Ordinatio means incorporation into an ordo. In the Church there are established bodies which Tradition, not without a basis in Sacred Scripture,4 has since ancient times called taxeis (Greek) or ordines. And so the liturgy speaks of the ordo episcoporum, the ordo presbyterorum, the ordo diaconorum. Other groups also receive this name of ordo: catechumens, virgins, spouses, widows,. . . .
1538 Integration into one of these bodies in the Church was accomplished by a rite called ordinatio, a religious and liturgical act which was a consecration, a blessing or a sacrament. Today the word "ordination" is reserved for the sacramental act which integrates a man into the order of bishops, presbyters, or deacons, and goes beyond a simple election, designation, delegation, or institution by the community, for it confers a gift of the Holy Spirit that permits the exercise of a "sacred power" (sacra potestas) which can come only from Christ himself through his Church. Ordination is also called consecratio, for it is a setting apart and an investiture by Christ himself for his Church. The laying on of hands by the bishop, with the consecratory prayer, constitutes the visible sign of this ordination.
II. THE SACRAMENT OF HOLY ORDERS IN THE ECONOMY OF SALVATION
The priesthood of the Old Covenant
1539 The chosen people was constituted by God as "a kingdom of priests and a holy nation. But within the people of Israel, God chose one of the twelve tribes, that of Levi, and set it apart for liturgical service; God himself is its inheritance. A special rite consecrated the beginnings of the priesthood of the Old Covenant. The priests are "appointed to act on behalf of men in relation to God, to offer gifts and sacrifices for sins.
1540 Instituted to proclaim the Word of God and to restore communion with God by sacrifices and prayer, this priesthood nevertheless remains powerless to bring about salvation, needing to repeat its sacrifices ceaselessly and being unable to achieve a definitive sanctification, which only the sacrifice of Christ would accomplish.
1541 The liturgy of the Church, however, sees in the priesthood of Aaron and the service of the Levites, as in the institution of the seventy elders,11 a prefiguring of the ordained ministry of the New Covenant. Thus in the Latin Rite the Church prays in the consecratory preface of the ordination of bishops:
God the Father of our Lord Jesus Christ, . . .
by your gracious word
you have established the plan of your Church.
From the beginning,
you chose the descendants of Abraham to be your holy nation.
You established rulers and priests
and did not leave your sanctuary without ministers to serve you. . . .
1542 At the ordination of priests, the Church prays:
Lord, holy Father, . . .
when you had appointed high priests to rule your people,
you chose other men next to them in rank and dignity
to be with them and to help them in their task. . . .
you extended the spirit of Moses to seventy wise men. . . .
You shared among the sons of Aaron
the fullness of their father's power.
- Catechism of the Catholic Church