St. Ambrose of Milan

“[Christ] made answer: ‘You are Peter, and upon this rock will I build my Church. . . . ’ Could he not, then, strengthen the faith of the man to whom, acting on his own authority, he gave the kingdom, whom he called the rock, thereby declaring him to be the foundation of the Church [Matt. 16:18]?” ( Exposition of the Christian Faith 4:5 [A.D. 379]).


“They (the Novatian heretics) have not the succession of Peter, who hold not the chair of Peter, which they rend by wicked schism; and this, too, they do, wickedly denying that sins can be forgiven (by the sacrament of confession) even in the Church, whereas it was said to Peter: ‘I will give unto thee the keys of the kingdom of Heaven, and whatsoever thou shalt bind on Earth, shall be bound in Heaven, and whatsoever thou shall loose on Earth shall be loosed in Heaven.’” (On Penance [A.D. 388]).


“And this confession is indeed rightly made by them, for they have not the succession of Peter, who hold not the chair of Peter, which they rend by wicked schism; and this, too, they do, wickedly denying that sins can be forgiven even in the Church, whereas it was said to Peter: “I will give unto thee the keys of the kingdom of heaven. and whatsoever thou shalt bind on earth shall be bound also in heaven, and whatsoever thou shall loose on earth shall be loosed also in heaven.” And the vessel of divine election himself said: “If ye have forgiven anything to any one, I forgive also, for what I have forgiven I have done it for your sakes in the person of Christ.” Why, then, do they read Paul’s writings, if they think that he has erred so wickedly as to claim for himself the right of his Lord? But he claimed what he had received, he did not usurp that which was not due to him.” (On Repentance).


“It is to Peter that he says: ‘You are Peter, and upon this rock I will build my Church’ [Matt. 16:18]. Where Peter is, there is the Church. And where the Church is, no death is there, but life eternal” (Commentary on Twelve Psalms of David 40:30 [A.D. 389]).


“Could not Christ, who confided to him the Kingdom by His own authority, have strengthened the faith of the one whom He designated a Rock to show the foundation of the Church?” (De Fide, bk. 4, n. 56).


“He (St. Peter), then, who before was silent, to teach us that we ought not to repeat the words of the impious, this one, I say, when he heard, ‘But who do you say I am,’ immediately, not unmindful of his station, exercised his primacy, that is, the primacy of confession, not of honor; the primacy of belief, not of rank.” (The Sacrament of the Incarnation of Our Lord).


“Faith, then, is the foundation of the Church, for it was not said of Peter’s flesh, but of his faith, that ‘the gates of hades shall not prevail against it.’ But his confession of faith conquered hades. And this confession did not shut out (even) one heresy, for, since the Church like a good ship is often buffeted by many waves, the foundation of the Church should prevail against all heresies.” (The Sacrament of the Incarnation of Our Lord).


“Believe, therefore, as Peter believed, that thou also mayest be blessed, and that thou also mayest deserve to hear, ‘Because flesh and blood hath not revealed it to thee, but My Father Who is in heaven, etc. ‘… Great is the grace of Christ, Who has imparted almost all His Own names to His disciples. ‘I am,’ said He, ‘the light of the world,’ and…, ‘Ye are the light of the world.’ ‘I am the living bread’; and ‘we all are one bread’ (1 Cor. x.17)…Christ is the rock, for ‘they drank of the same spiritual rock that followed them, and the rock was Christ’ (1 Cor. x.4); also He denied not to His disciple the grace of this name; that he should be Peter (petrus), because he has from the Rock (petra) the solidity of constancy, the firmness of faith. Make an effort, therefore, to be a rock! Do not seek the rock outside of yourself, but within yourself! Your rock is your deed, your rock is your mind. Upon this rock your house is built. Your rock is your faith, and faith is the foundation of the Church. If you are a rock, you will be in the Church, because the Church is on a rock. If you are in the Church the gates of hell will not prevail against you." (Commentary on Luke).


“[No disturbance should strike] the Roman Church, the Head of the whole Roman world… for from thence flow all the rights of venerable Communion to all persons.” (Letter to Emperor Gratian).


“But he was not so eager as to lay aside caution. He called the bishop to him, and esteeming that there can be no true thankfulness except it spring from true faith, he enquired whether he agreed with the Catholic bishops, that is, with the Roman Church? (On the Death of Satyrus).


“This man who at first was silent, as he teaches that we ought not to repeat the words of the wicked, when he heard : "Who do ye say that I am?", at once mindful of his place, assumed the primacy : undoubtedly a primacy of confession, not of honour; a primacy of faith, not of rank. That is to say, "Now let no one surpass me". (Liber de Incarnationis Dominicae Sacramento [A.D. 381]).


“There is no doubt, therefore, that Peter believed, and that he believed because he loved, and loved because he believed. Consequently he is also made sad, because he is asked yet a third time : " Lovest thou me?"For he about whom there is a doubt is questioned, but the Lord is not in doubt, and he was asking the question, not in order to get information, but in order to teach him whom he was leaving for us, as a vicar of his love, seeing that he was to be raised into heaven. For thus you find 1 " Simon, son of John, lovest thou me? " Likewise " Lord, thou knowest that I love thee", and Jesus says, " Feed my lambs ". In full self-awareness, Peter testifies to a love not assumed for the occasion, but long since known to God. For who else is there that could easily make this profession about himself? And for that very reason, he alone of all men makes it : he is placed before all men; for love is greater than all.” (Expositio in Lucam, Book 10. [A.D. 390])


“Again there was Peter, and he followed him when he was led by the Jews to the house of Caiaphas, chief of the synagogue. That is Peter to whom he said, "Thou art Peter and upon this rock I will build my Church ". Where therejiore Peter is, there is the Church. Where the Church is, there is no death but eternal life. And he also adds, "And the gates of hades shall not prevail against it, and I will give to thee the keys of the kingdom of heaven". Against blessed Peter, neither has the gate of hades prevailed, nor the gate of heaven shut, but on the contrary he has destroyed the forecourt of hades and thrown open the heavenly one.” (Enarratio in Psalmurn XL [A.D. 395]).


“Peter is sifted, as he is driven on to deny Christ. He falls into temptation, speaking like a man full of chaff. . . . In the end he wept and washed away his chaff, and by those temptations, he was worthy that Christ should intervene for him. . . . At length, after being tempted by the devil, Peter is set over the Church. And so the Lord indicated beforehand that which happened later, namely that he chose him as shepherd of his flock; for he said to him, "When thou art converted, strengthen thy brethren". And so the holy apostle Peter is converted to good fruit, and sifted like wheat, that he with the saints of the Lord might be one bread which should be our food.” (Enarratio in Psalmum XLIII [A.D. 397).


“Nothing is to be taken away from the apostolic writings, and nothing is to be added to them; and in the same way we must expunge nothing from the creed drawn up and handed down by the apostles, nor must we add anything to it. This is the creed which the Roman church holds, where Peter, the first of the apostles, sat, and thither he brought the common decision.” (Explanatio Symboli ad Initiandos).