What are the names of the sacraments that serve to build up communion in the Church?
Someone who is baptized and confirmed can receive moreover a special mission in the Church in two special sacraments and thus be enlisted in the service of God: Holy Orders and Matrimony.
The two sacraments have something in common: They are directed to the good of others. No one is ordained just for himself, and no one enters the married state merely for his own sake. The sacrament of Holy Orders and the sacrament of Matrimony are supposed to build up the People of God; in other words, they are a channel through which God pours out love into the world.
What happens in Holy Orders?
The man who is ordained receives a gift of the Holy Spirit that gives him a sacred authority that is conferred upon him by Christ through the bishop.
Being a priest does not mean just assuming an office or a ministry. Through Holy Orders a priest receives as a gift a definite power and a mission for his brothers and sisters in faith. (YOUCAT questions 248 & 249)
Dig Deeper: CCC section (1533-1538) and other references here.
Part 2: The Celebration of the Christian Mystery (1066 - 1690)
Section 2: The Seven Sacraments of the Church (1210 - 1690)
Chapter 3: The Sacraments at the Service of Communion (1533 - 1666)
Baptism, Confirmation, and Eucharist are sacraments of Christian initiation. They ground the common vocation of all Christ's disciples, a vocation to holiness and to the mission of evangelizing the world. They confer the graces needed for the life according to the Spirit during this life as pilgrims on the march towards the homeland.
Two other sacraments, Holy Orders and Matrimony, are directed towards the salvation of others; if they contribute as well to personal salvation, it is through service to others that they do so. They confer a particular mission in the Church and serve to build up the People of God.
Through these sacraments those already consecrated by Baptism and Confirmation1 for the common priesthood of all the faithful can receive particular consecrations. Those who receive the sacrament of Holy Orders are consecrated in Christ's name "to feed the Church by the word and grace of God."2 On their part, "Christian spouses are fortified and, as it were, consecrated for the duties and dignity of their state by a special sacrament."3
1.
Cf. LG 10.
2.
LG 11 § 2.
3.
GS 48 § 2.
Article 6: The Sacrament of Holy Orders (1536 - 1600)
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"? ⇡
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,. ...
4.
Cf. Heb 5:6; 7:11; Ps 110:4.
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)5 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.
5.
Cf. LG 10.