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, and the gates of the netherworld shall not prevail against it. 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.’ (Mt 16:16-19)

Then he summoned his twelve disciples and gave them authority over unclean spirits to drive them out and to cure every disease and every illness. The names of the twelve apostles are these: first, Simon called Peter, and his brother Andrew; James, the son of Zebedee, and his brother John; Philip and Bartholomew, Thomas and Matthew the tax collector; James, the son of Alphaeus, and Thaddeus; Simon the Cananean, and Judas Iscariot who betrayed him. (Mt 10:1-4)

That he was buried; that he was raised on the third day in accordance with the scriptures; that he appeared to Kephas, then to the Twelve. After that, he appeared to more than five hundred brothers at once, most of whom are still living, though some have fallen asleep. (1Cor 15:4-6)

Then after three years I went up to Jerusalem to confer with Kephas and remained with him for fifteen days. Then after fourteen years I again went up to Jerusalem with Barnabas, taking Titus along also.  I went up in accord with a revelation, and I presented to them the gospel that I preach to the Gentiles – but privately to those of repute – so that I might not be running, or have run, in vain. (Gal 1:18; 2:1-2)

During those days Peter stood up in the midst of the brothers (there was a group of about one hundred and twenty persons in the one place). He said, ‘My brothers, the scripture had to be fulfilled which the holy Spirit spoke beforehand through the mouth of David.’ (Acts 1:15-16)

They were all astounded and bewildered, and said to one another, ‘What does this mean?’ But others said, scoffing, ‘They have had too much new wine.’ Then Peter stood up with the Eleven, raised his voice, and proclaimed to them, ‘You who are Jews, indeed all of you staying in Jerusalem. Let this be known to you, and listen to my words.’ (Acts 2:12-14)

Lastly, St. Ambrose says: Because he alone of all of them professed (Christ) he was placed above all. (St. Ambrose, cited by the Catechism of Trent, Article IX – The marks of the Church: unity in government)

But if anyone should affirm that all Christians without distinction are priests of the New Testament, or that they are all endowed among themselves with an equal spiritual power, he seems to do nothing else than disarrange [can. 6] the ecclesiastical hierarchy, which is ‘as an army set in array’ (cf. Song 6:3), just as if, contrary to the teaching of blessed Paul, all were apostles, all prophets, all evangelists, all pastors, all doctors (cf. 1Cor 12:29 Eph 4:11). (Council of Trent, Session XXIII, The Doctrine on the Sacrament of Orders, Ch. 4, The Ecclesiastical Hierarchy and Ordination, July 15, 1563)

The Scripture teaches us, and the tradition of the Fathers confirms the teaching, that the Church is the mystical body of Christ, ruled by the Pastors and Doctors (1Eph 4:2 ss) – a society of men containing within its own fold chiefs who have full and perfect powers for ruling, teaching and judging (Mt 28:18-20, 16:18-19, 18:17, Tit 2:15, 2Cor 10:6, 13:10, etc.) It follows that the Church is essentially an unequal society, that is, a society comprising two categories of persons, the Pastors and the flock, those who occupy a rank in the different degrees of the hierarchy and the multitude of the faithful. So distinct are these categories that with the pastoral body only rests the necessary right and authority for promoting the end of the society and directing all its members towards that end. (Pius X. Encyclical Vehementer nos, February 11, 1906)

To your inquiry we do not deny a legal reply, because we, upon whom greater zeal for the Christian religion is incumbent than upon the whole body, out of consideration for our office do not have the liberty to dissimulate, nor to remain silent. We carry the weight of all who are burdened; nay rather the blessed apostle Peter bears these in us, who, as we trust, protects us in all matters of his administration, and guards his heirs. (Denzinger-Hünermann 181 – St. Siricius, Epistle Directa ad decessorem to Himerius, Bishop of Terracina, February 10, 385)

‘Servus servorum Dei’: it is known that this title, chosen by him [saint Gregory the Great] ever since he was a deacon – and used in not a few of his letters – gradually became a traditional title and almost a definition of the person of the Bishop of Rome. It is also certain, that from sincere humility,  he made it the motto of his ministry and that, precisely because of his universal function in the Church of Christ, he always considered and showed himself to be the maximum and primary servant – the servant of the servants of God – servant of all, following the example of Christ himself, who had explicitly affirmed that he ‘came not to be served but to serve, and to give his life as a ransom for many’ (Mt 20:28). Most profound was, therefore, his consciousness of the dignity [of the Papacy], which he accepted with great trepidation after having unsuccessfully tried to remain hidden in an attempt to avoid it; but, at the same time, possessing a clear awareness of his duty to serve, convinced himself and attempting to instill in the others the conviction that all authority, above all within the Church, is essentially service. The awareness of his own pontifical office and, proportionally, of all pastoral ministry, is condensed in the word ‘responsibility’: he who exercises an ecclesiastical ministry should respond for what he does, not only to men, not only to the souls that were confided to him, but also and in the first place to God and to his Son, in whose name he acts each time he distributes the supernatural treasures of grace, announces the truths of the Gospel and undertakes activities of  legislation and of government. (John Paul II. Apostolic Letter Plurimum significans, June 29, 1990)

The Good Shepherd, the Lord Christ Jesus (cf. Jn 10: 11, 14), conferred on the bishops, the successors of the Apostles, and in a singular way on the bishop of Rome, the successor of Peter, the mission of making disciples in all nations and of preaching the Gospel to every creature. […] This applies to each and every bishop in his own particular Church; but all the more does it apply to the bishop of Rome, whose Petrine ministry works for the good and benefit of the universal Church. The Roman Church has charge over the ‘whole body of charity’ and so it is the servant of love. It is largely from this principle that those great words of old have come — ‘The servant of the servants of God’ —, by which Peter’s successor is known and defined. (John Paul II. Apostolic Constitution Pastor bonus, no. 2, June 28, 1998)

The Roman Pontiff, to whom Christ the Lord instituted as visible Head of his Body, which is the Church, and desired that he bear the solicitude for all of the Churches, called and assumed many collaborators for an immense responsibility…so that, sharing with them (that is, the cardinals) and the other magistrates of the Roman Curia, the vast bulk of cares and concerns, the holder of the great power of the keys, with the help of divine grace, would not yield. (Sixtus V. Constitution Immensa aeterni, February 11, 1588)

The institution of the nascent universal Church took origin from the office of Blessed Peter, in which consists its direction and apex. In effect, from this source flowed, in accordance with the development of religion, the ecclesiastic discipline in all of the Churches. The definitions of the Council of Nicaea do not testify anything else; in effect, it did not dare to establish anyone above him, since it acknowledged that no one may be put above his rank, and lastly it understood that all had been granted to him by the Lord’s word. It is certain that this Roman Church is for all of the other churches, spread around the world, just as a head is for the members. (Denzinger-Hünermann 233, Epistle Insitutio to the Bishops of Thessaly, March 11, 422)

Also this same holy Roman Church holds the highest and complete primacy and spiritual power over the universal Catholic Church which she truly and humbly recognizes herself to have received with fullness of power from the Lord Himself in Blessed Peter, the chief or head of the Apostles whose successor is the Roman Pontiff. And just as to defend the truth of Faith she is held before all other things, so if any questions shall arise regarding faith they ought to be defined by her judgment. (Denzinger-Hünermann 861, II Council of Lyon, Profession of Faith of the emperor Michael Palaeologus before Gregory X, July 6, 1274)

We likewise define that the holy Apostolic See and the Roman Pontiff hold the primacy throughout the entire world; and that the Roman Pontiff himself is the successor of blessed Peter, the chief of the Apostles, and the true vicar of Christ, and that he is the head of the entire Church, and the father and teacher of all Christians; and that full power was given to him in blessed Peter by our Lord Jesus Christ, to feed, rule, and govern the universal Church; just as is contained in the acts of the ecumenical Councils and in the sacred canons. (Denzinger-Hünermann 1307. Council of Florence – Ecumenical XVII, Bula Laetentur caeli on union with the Greeks, July 6, 1439)

Indeed no true and perfect human society can be conceived which is not governed by some supreme authority. Christ therefore must have given to His Church a supreme authority to which all Christians must render obedience. […] Certainly Christ is a King for ever; and though invisible, He continues unto the end of time to govern and guard His church from Heaven. But since He willed that His kingdom should be visible He was obliged, when He ascended into Heaven, to designate a vice-gerent on earth. […] It is clear that by the will and command of God the Church rests upon St. Peter, just as a building rests on its foundation. Now the proper nature of a foundation is to be a principle of cohesion for the various parts of the building. It must be the necessary condition of stability and strength. Remove it and the whole building falls. It is consequently the office of St. Peter to support the Church, and to guard it in all its strength and indestructible unity. How could he fulfil this office without the power of commanding, forbidding, and judging, which is properly called jurisdiction? (Leo XIII. Encyclical Satis cognitum, nos. 11-12, June 29, 1896)

That there is unity in the administration of the Catholic Church is evident. For as the faithful are subject to their priests, so are priests to their bishops, whom ‘the Holy Spirit has placed……to rule the Church of God’ (Acts 20:28). So, too, every bishop is subject to the Roman pontiff, the successor of Saint Peter, whom Christ called a rock and made the foundation of His Church. (Mt 16:18) It was to Peter that Christ gave in a special way the power to bind and loose on earth, (Mt 16:19) to strengthen his brethren, (Lk 22:32) to feed the entire flock. (Jn 21:15-17) (John XXIII. Encyclical Ad Petri cathedram, June 29, 1959)

The Bishop of the Roman Church, in whom continues the office given by the Lord uniquely to Peter, the first of the Apostles, and to be transmitted to his successors, is the head of the college of bishops, the Vicar of Christ, and the pastor of the universal Church on earth. By virtue of his office he possesses supreme, full, immediate, and universal ordinary power in the Church, which he is always able to exercise freely. (Code of Canon Law, Can. 331)

Furthermore if you have not heard us, it remains for you to be with us of necessity, such as our Lord Jesus Christ has commanded those to be considered, who disdained to hear the Church of God, especially since the privileges of the Roman Church, built on Blessed Peter by the word of Christ, deposited in the Church herself, observed in ancient times and celebrated by the sacred universal Synods, and venerated jointly by the entire Church, can by no means be diminished, by no means infringed upon, by no means changed; for the foundation which God has established, no human effort has the power to destroy and what God has determined, remains firm and strong. . . . Thus the privileges granted to this holy Church by Christ, not given by the Synod, but now only celebrated and venerated. . . . (Denzinger-Hünermann 640, Epistle Proposueramus quidem of Nicholas I to Michael the Emperor, September 28, 865)

But we must not think that He rules only in a hidden (Cf. Leo XIII, Satis Cognitum: A.S.S., XXVIII, 725) or extraordinary manner. On the contrary, our Redeemer also governs His Mystical Body in a visible and normal way through His Vicar on earth. You know, Venerable Brethren, that after He had ruled the ‘little flock’ (Lk 12:32) Himself during His mortal pilgrimage, Christ our Lord, when about to leave this world and return to the Father, entrusted to the Chief of the Apostles the visible government of the entire community He had founded. (Pius XII. Encyclical Mystici Corporis Christi, no. 40, June 29, 1943)

But this authority, although it is given to man and is exercised by man, is not human, but rather divine, and has been given by the divine Word to Peter himself and to his successors in him, whom the Lord acknowledged an established rock, when he said to Peter himself: ‘Whatsoever you shall bind’ etc. (Denzinger-Hünermann 874, Boniface VIII – Bull Unum sanctam, November 18, 1302)

No one doubts, but rather it has been known to all generations, that the holy and most blessed Peter, chief and head of the Apostles, the pillar of the faith, the foundation stone of the Catholic church, received the keys of the kingdom from our Lord Jesus Christ the Savior and Redeemer of the human race, and that the power of binding and loosing sins was given to him, who up to this moment and always lives in his successors, and judges. (Denzinger-Schönmetzer 112. Council of Ephesus, Ecumenical III (431) Session III, on the Primacy of the Roman Pontiff)

Peter is made the foundation, because he says: Thou art Christ, the Son of the Living God; and hears in reply that he is a rock. But although a rock, he is not such a rock as Christ; for Christ is truly an immovable rock, but Peter, only by virtue of that rock. For Jesus bestows His dignities on others; He is a priest, and He makes priests; a rock, and He makes a rock; what belongs to Himself, He bestows on His servants. (St. Basil the Great, cited by the Catechism of Trent, Article IX (‘I Believe in the Holy Catholic Church..’) – Unity in Government)

The watchful care over the universal Church confided to Peter abides with him by reason of the Lord’s statement; for he knows on the testimony of the Gospel (Mt 16:18) that the Church was founded on him. His office can never be free from cares, since it is certain that all things depend on his deliberation. (Denzinger-Hünermann 234 – St. Boniface I, Epistle Manet beatum to Rufus and the other Bishops throughout Macedonia, March 11, 422)

With how great care and pastoral vigilance the Roman Pontiffs, our predecessors, fulfilling the duty and office committed to them by the Lord Christ Himself in the person of most Blessed Peter, Prince of the Apostles, of feeding the lambs and the sheep, have never ceased sedulously to nourish the Lord’s whole flock with words of faith and with salutary doctrine, and to guard it from poisoned pastures, is thoroughly known to all, and especially to you, Venerable Brethren. (Pius IX. Encyclical Quanta cura, no.1, December 8, 1864)

In short, Venerable Brethren, there are three policies which principally exercise Our mind when We reflect on the enormous responsibility for the Church of Christ which, unsought and undeserved, the providence of God has laid upon Us in making Us Bishop of Rome, successor to St. Peter the Apostle and Key-bearer of the Kingdom of Heaven, and Vicar of Christ who appointed Peter the first Shepherd of his worldwide flock. First We are convinced that the Church must look with penetrating eyes within itself, ponder the mystery of its own being, and draw enlightenment and inspiration from a deeper scrutiny of the doctrine of its own origin, nature, mission, and destiny.  (Paul VI. Encyclical Ecclesiam suam, nos. 8-9, August 6, 1964)