And there shall be one fold, one shepherd [Jn 10:16]
Bishops as Shepherds
The authority of the Catholic Church rests with the bishops who oversee the work of the priests and deacons. Bishops include bishops, archbishops, and the Pope, who is also the Bishop of Rome. Pope Francis, when talking to a group of recently appointed bishops in 2013, commented that the three components of tending the flock are “welcoming magnanimously, walking with the flock, and staying with the flock.”
Further describing his view of the role of Bishops in today’s society the Pope went on to state at a meeting of the American Bishops in 2015:
“May bishops be shepherds, close to the people; fathers and brothers, may they be gentle, patient and merciful; may they love poverty, interior poverty, as freedom for the Lord, and exterior poverty, as well as simplicity and a modest lifestyle; may they not have the mindset of ‘princes’. Be careful that they are not ambitious, that they are not in quest of the episcopate, that they are espoused to the Church, without constantly seeking another; this is called adultery. May they be overseers of the flock that has been entrusted to them, to take care of everything that is needed to keep it united.”
Establishment of the Priesthood
From the beginning, Jesus came to tend to his flock. His parable on the lost sheep in [Lk 15:3-7] demonstrates his philosophy on the importance of saving souls despite the cost to the shepherd:
What man among you having a hundred sheep and losing one of them would not leave the ninety-nine in the desert and go after the lost one until he finds it? And when he does find it, he sets it on his shoulders with great joy and, upon his arrival home, he calls together his friends and neighbors and says to them, ‘Rejoice with me because I have found my lost sheep.’ I tell you, in just the same way there will be more joy in heaven over one sinner who repents than over ninety-nine righteous people who have no need of repentance.
This was also a message in the Old Testament [Ez 34:14-16]:
There they will lie down on good grazing ground; in rich pastures they will be pastured on the mountains of Israel. I myself will pasture my sheep; I myself will give them rest—oracle of the Lord God. The lost I will search out, the strays I will bring back, the injured I will bind up, and the sick I will heal; but the sleek and the strong I will destroy. I will shepherd them in judgment.
Over his three-year ministry, Jesus selected his apostles, who would be the shepherds of his Church, from his flock. They were not prominent figures or princes -- many of them were fishermen, while one was even a tax collector, an occupation hated by most. He called the Apostle Peter his “Rock” because God had revealed to Peter that Jesus was the Son of the living God [Mt 16:15-18]:
He said to them, “But who do you say that I am?” Simon Peter said in reply, “You are the Messiah, the Son of the living God.” Jesus said to him in reply, “Blessed are you, Simon son of Jonah. For flesh and blood has not revealed this to you, but my heavenly Father. And so I say to you, you are Peter, and upon this rock I will build my church,[c]and the gates of the netherworld shall not prevail against it.
Then Jesus gave Peter the keys to the kingdom of heaven, making him the head of the apostles and his future church [Mt 16:19]:
I will give you the keys to the kingdom of heaven. Whatever you bind on earth shall be bound in heaven; and whatever you loose on earth shall be loosed in heaven.”
This act of conveying the authority of the church onto Peter is pre-figured in the Old Testament and is the scriptural basis for Papal authority/autonomy in the Catholic church [Is 22:20-23]:
On that day I will summon my servant Eliakim, son of Hilkiah; I will clothe him with your robe, gird him with your sash, give over to him your authority. […] I will place the key of the House of David on his shoulder; what he opens, no one shall shut, what he shuts, no one shall open. I will fix him like a peg in a sure spot, to be a place of honor for his family;
Jesus commissioned his apostles to build his Church and gave them authority to “make disciples of all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Spirit, teaching them to observe all that I have commanded you” [Mt 28:18-19]. He had instructed his Apostles on the principles and sacraments of his church.
He said to them, "Go into the whole world and proclaim the gospel to every creature."
Jesus answered and said to him, "Amen, amen, I say to you, no one can enter the kingdom of God without being born of water and Spirit."
"...As the Father has sent me, so I send you." And when he had said this, he breathed on them, "Receive the holy Spirit."
"Whose sins you forgive are forgiven them, and whose sins you retain are retained."
Jesus took bread,said the blessing, broke it, and giving it to his disciples said, "Take and eat; this is my body." Then he took a cup, gave thanks, and gave it to them saying, "Drink from it, all of you, for this is my blood of the covenant, which will be shed on behalf of many for the forgiveness of sins."
"Therefore, what God has joined together, no human being must separate. ... I say to you, whoever divorces his wife (unless the marriage is unlawful) and marries another commits adultery."
Anointing of the Sick
... they anointed with oil many who were sick and cured them.
Furthermore, Jesus gave them the power through the Holy Spirit to accomplish these tasks [Jn 14:26]:
The Advocate, the holy Spirit that the Father will send in my name – he will teach you everything and remind you of all that [I] told you.
The early church hierarchical structure evolved beginning with St. Peter as the head of the church and the other apostles as bishops. As the number of disciples grew, it was understood that more structure was needed to serve the corporal needs of the new Christians so the Apostles could devote themselves to prayer and evangelization. Hence, the office of deacon was added [Acts 6:2-4]:
So the Twelve called together the community of the disciples and said, “It is not right for us to neglect the word of God to serve at table. Brothers, select from among you seven reputable men, filled with the Spirit and wisdom, whom we shall appoint to this task, whereas we shall devote ourselves to prayer and to the ministry of the word.”
Acts 14:23 refers to Paul and Barnabas appointing presbyters (priests) in each parish during their travels:
They appointed presbyters for them in each church, and with prayer and fasting, commended them to the Lord in whom they had put their faith.
St. Paul tells Timothy that “if any one aspires to the office of bishop, he desires a noble task” [1Tm 3:1], indicating the position’s importance.
The structure which holds today of Bishops, Priests, and Deacons evolved quickly in the Early Church out of need. The responsibilities of the three offices are summarized in the Catechism of the Catholic Church [1592-1596]:
1592. The ministerial priesthood differs in essence from the common priesthood of the faithful because it confers a sacred power for the service of the faithful. The ordained ministers exercise their service for the People of God by teaching (munus docendi), divine worship (munus liturgicum) and pastoral governance (munus regendi).
1593. 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 (cf. St. Ignatius of Antioch, Ad Trall. 3,1).
1594. The bishop receives the fullness of the sacrament of Holy Orders, which integrates him into the episcopal college and makes 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.
1595. 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 presbyterium 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.
1596. Deacons are ministers 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.
Bishops perform the sacrament of Holy Orders to consecrate all three degrees of the priesthood. It is conferred by the laying on of hands followed by prayers to God for acquisition of the graces of the Holy Spirit required for the ministry just as it was by the Apostles during the beginning of the Church [2Tm 1:6]:
For this reason, I remind you to stir into flame the gift of God that you have through the imposition of my hands.
See Article 6 of the Catechism of the Catholic Church [1536-1600] for a complete review of the Sacrament of the Holy Orders.