“As a way of showing forth the Church's holiness, it is to be recognized that the consecrated life, which mirrors Christ's own way of life, has an objective superiority. Precisely for this reason, it is an especially rich manifestation of Gospel values and a more complete expression of the Church's purpose, which is the sanctification of humanity. The consecrated life proclaims and in a certain way anticipates the future age, when the fullness of the Kingdom of Heaven, already present in its first fruits and in mystery, will be achieved and when the children of the resurrection will take neither wife nor husband, but will be like the angels of God (cf. Mt. 22:30)”
Pope John Paul II Vita Consecrata, no. 32
In Persona Christi
In the ecclesial service of the ordained minister, it is Christ himself who is present to his church as Head of his Body, Shepherd of his flock, high priest of the redemptive sacrifice, Teacher of Truth. This is what the Church means by saying that a priest, by virtue of the sacrament of Holy Orders, acts in persona Christi Capitis.
It is the same priest, Christ Jesus, whose sacred person his minister truly represents. Now the minister, by reason of the sacerdotal consecration which he has received, is truly made like to the high priest and possesses the authority to act in the power and place of the person of Christ himself.
Christ is the source of all priesthood: the pries of the old law was a figure of Christ, and the priest of the new law acts in the person of Christ (St. Thomas Aquinas quoted in CCC 1548)
. . . “in the name of the whole Church”
The ministerial priesthood has the task not only of representing Christ—Head of the Church—before the assembly of the faithful, but also of acting in the name of the whole Church when presenting to God the prayer of the Church, and above all when offering the Eucharistic sacrifice (CCC1552).
Three Degrees of the Sacrament of Holy Orders
Since the beginning, the ordained ministry has been conferred and exercised in three degrees: that of bishops, that of presbyters, and that of deacons. The ministries conferred by ordination are irreplaceable for the organic structure of the Church: without the bishop, presbyters, and deacons, one cannot speak of the Church (CCC1593).
Deacons are minister ordained for tasks of service of the Church; they do not receive the ministerial priesthood, but ordination confers on them important functions in the ministry of the word, divine worship, pastoral governance, and the service of charity, tasks which they must carry out under the pastoral authority of their bishop (CCC 1596).
Deacons share in Christ’s mission and grace in a special way. The sacrament of Holy Orders marks them with an imprint which cannot be removed and which configures them to Chris, who made himself the “deacon” or servant of all. Among other tasks, it is the task of deacons to assist the bishop and priests in the celebration of the divine mysteries, above all the Eucharist, in the distribution of Holy Communion, in assisting at and blessing marriages, in the proclamation of the Gospel and preaching, in presiding over funerals, and in dedicating themselves to the various ministries of charity (CCC 1570).
Since the Second Vatican Council the Latin Church [Roman Church] has restored the diaconate “as a proper and permanent rank of the hierarchy,” while the Churches of the East had always maintained it. This permanent diaconate, which can be conferred on married men, constitutes an important enrichment for the Church’s mission. Indeed it is appropriate and useful in its liturgical and pastoral life or whether in its social and charitable works, should “be strengthened by the imposition of hands which has come down form the apostles. They would be more closely bound to the altar and their ministry would be made more fruitful through the sacramental grace of the diaconate (CCC 1571).
Priests are united with the bishops in sacerdotal dignity and at the same time depend on them in the exercise of their pastoral functions; they are called to be the bishops’ prudent co-workers. they form around their bishop the prebyterium which bears responsibility with him for the particular Church. They receive from the bishop the charge of a parish community or a determinate ecclesial office. (CCC 1595)
Through the sacrament of Holy Orders priests share in the universal dimensions of the mission that Christ entrusted to the apostles. The spiritual gift they have received in ordination prepares them, not for a limited and restricted mission, “but for the fullest, in fact the universal mission of salvation’ to the end of the earth,’” prepared in spirit to preach the Gospel everywhere (CCC1565).
“It is in the Eucharistic cult or in the Eucharistic assembly of the faithful (synaxis) that they exercise in a supreme degree their sacred office; there, acting in the person of Christ and proclaiming his mystery, they untie the votive offerings of the faithful to the sacrifice of Christ their head, and in the sacrifice of the Mass they make present again and apply, until the coming of the Lord, the unique sacrifice of the New Testament, that namely of Christ offering himself once for all a spotless victim to the Father.” From this unique sacrifice their whole priestly ministry draws its strength (CCC1566).
The bishop received the fullness of the sacrament of Holy Orders, which integrates him into the Episcopal college and make him the visible head of the particular Church entrusted to him. As successors of the apostles and members of the college, the bishops share in the apostolic responsibility and mission of the whole Church under the authority of the Pope, successor of St. Peter (CCC1594).
“Episcopal consecration confers, together with the office of sanctifying, also the offices of teaching and ruling...In fact...by the imposition of hands and through he words of consecration, the grace of the Holy Spirit is given, and a cared character is impressed in such wise that bishops, in an eminent and visible manner, take the place of Christ himself, teacher, shepherd, and priest, and act as his representative (in Eius persona agant).” “By virtue, therefore, of the Holy Spirit who has been given to them, bishops have been constituted true and authentic teachers of the faith and have been made pontiffs and pastors (CCC 1558).
As Christ’s vicar, each bishop has the pastoral care of the particular Church entrusted to him, but a the same time he bears collegially with all his brothers in the episcopacy thesolicitude for all the Churches: “Though each bishop is the lawful pastor only of the portion of the flock entrusted to his care, as a legitimate successor of the apostles he is, by divine institution and precept, responsible with the other bishops for the apostolic mission of the Church (CCC 1560).
CATECHISM OF THE CATHOLIC CHURCH - 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."
CCC 1536 by USCCB.org
CANON LAW 1008 - TITLE VI: HOLY ORDERS
"By divine institution some among Christ's faithful are, through the sacrament of order, marked with an indelible character and are thus constituted sacred ministers; thereby they are consecrated and deputed so that, each according to his own grade, they fulfill, in the person of Christ the Head, the offices of teaching, sanctifying and ruling, and so they nourish the people of God."
CATHOLIC ENCYCLOPEDIA: HOLY ORDERS
"The Sacrament of 'Holy Orders' is the sacrament by which grace and spiritual power for the discharge of ecclesiastical offices are conferred."