St Augustine was a Catholic Bishop of Hippo who lived from 354ad-430ad. He is a father and doctor of the Catholic Church but is also well respected by protestants. Protestants sometimes try to argue that Augustine was protestant and certainly not a Catholic so the following are citations from the works of St Augustine to show that he was not just historically Catholic but Catholic by what he taught and by him calling himself Catholic.
Baptism
The City of God (Book XXII)
"Cyprian was not issuing a new decree but was keeping to the most solid belief of the Church in order to correct some who thought that infants ought not be baptized before the eighth day after their birth. . . . He agreed with certain of his fellow bishops that a child is able to be duly baptized as soon as he is born" (Letters 166:8:23 [A.D. 412]).
Tractate 6 (John 1:32-33)
"By this grace baptized infants too are in grafted into his [Christ's] body, infants who certainly are not yet able to imitate anyone. Christ, in whom all are made alive . . . gives also the most hidden grace of his Spirit to believers, grace which he secretly infuses even into infants. . . . It is an excellent thing that the Punic [North African] Christians call baptism salvation and the sacrament of Christ's Body nothing else than life. Whence does this derive, except from an ancient and, as I suppose, apostolic tradition, by which the churches of Christ hold inherently that without baptism and participation at the table of the Lord it is impossible for any man to attain either to the kingdom of God or to salvation and life eternal? This is the witness of Scripture, too. . . . If anyone wonders why children born of the baptized should themselves be baptized, let him attend briefly to this. . . . The sacrament of baptism is most assuredly the sacrament of regeneration" (Forgiveness and the Just Deserts of Sin, and the Baptism of Infants 1:9:10; 1:24:34; 2:27:43 [A.D. 412]).
Tractate 15 (John 4:1-42)
"The custom of Mother Church in baptizing infants is certainly not to be scorned, nor is it to be regarded in any way as superfluous, nor is it to be believed that its tradition is anything except apostolic" (The Literal Interpretation of Genesis 10:23:39 [A.D. 408]).
On Baptism, Against the Donatist book IV
"That the place of baptism is sometimes supplied by suffering is supported by a substantial argument which the same blessed Cyprian draws from the circumstance of the thief, to whom, although not baptized, it was said, 'Today you shall be with me in paradise' [Luke 23:43]. Considering this over and over again, I find that not only suffering for the name of Christ can supply for that which is lacking by way of baptism, but even faith and conversion of heart [i.e., baptism of desire] if, perhaps, because of the circumstances of the time, recourse cannot be had to the celebration of the mystery of baptism"
On Baptism,
"When we speak of within and without in relation to the Church, it is the position of the heart that we must consider, not that of the body. . . . All who are within [the Church] in heart are saved in the unity of the ark [by baptism of desire]"
Tractate 4 (John 1:19-33)
"Those who, though they have not received the washing of regeneration, die for the confession of Christ-it avails them just as much for the forgiveness of their sins as if they had been washed in the sacred font of baptism. For he that said, 'If anyone is not reborn of water and the Spirit, he will not enter the kingdom of heaven' [John 3:5], made an exception for them in that other statement in which he says no less generally, 'Whoever confesses me before men, I too will confess him before my Father, who is in heaven' [Matt. 10:32]" (The City of God 13:7 [A.D. 419]).
Tractate 6 (John 1:32-33)
"[According to] apostolic tradition . . . the churches of Christ hold inherently that without baptism and participation at the table of the Lord it is impossible for any man to attain either to the kingdom of God or to salvation and life eternal. This is the witness of Scripture too" (Forgiveness and the Just Deserts of Sin, and the Baptism of Infants 1:24:34 [A.D. 412]).
Tractate 13 (John 3:22-29)
"There are three ways in which sins are forgiven: in baptism, in prayer, and in the greater humility of penance; yet God does not forgive sins except to the baptized" (Sermons to Catechumens on the Creed 7:15 [A.D. 395]).
Eucharist
Letter 54 (A.D. 400)
4. Some one may say, "The Eucharist ought not to be taken every day." You ask, "On what grounds?" He answers, sacrament, he ought to choose those days upon which he lives in more special purity and self-restraint; for whosoever eateth and drinketh unworthily, eateth and drinketh judgment to himself.'" Another answers, "Certainly; if the wound inflicted by sin and the violence of the soul's distemper be such that the use of these remedies must be put off for a time, every man in this case should be, by the authority of the bishop, forbidden to approach the altar, and appointed to do penance, and should be afterwards restored to privileges by the same authority; for this would be partaking unworthily, if one should partake of it at a time when he ought to be doing penance; and it is not a matter to be left to one's own judgment to withdraw himself from the communion of the Church, or restore himself, as he pleases. If, however, his sins are not so great as to bring him justly under sentence of excommunication, he ought not to withdraw himself from the daily use of the Lord's body for the healing of his soul." Perhaps a third party interposes with a more just decision of the question, reminding them that the principal thing is to remain united in the peace of Christ, and that each should befree to do what, according to his belief, he conscientiously regards as his duty. For neither of them lightly esteems the Body and Blood of the Lord; on the contrary, both are contending who shall most highly honour the sacrament fraught with blessing. There was no controversy between those two mentioned in the Gospel, Zacchaeus and the Centurion; nor did either of them think himself better than the other, though, whereas the former received the Lord joyfully into his house, the latter said,
Tractate 6 (John 1:32-33)
"I promised you [new Christians], who have now been baptized, a sermon in which I would explain the sacrament of the Lord's Table. . . . That bread which you see on the altar, having been sanctified by the word of God, is the body of Christ. That chalice, or rather, what is in that chalice, having been sanctified by the word of God, is the blood of Christ" (Sermons 227 [A.D. 411]).
Confession
Tractate 41 (John 8:31-36)
"When you shall have been baptized, keep to a good life in the commandments of God so that you may preserve your baptism to the very end. I do not tell you that you will live here without sin, but they are venial sins which this life is never without. Baptism was instituted for all sins. For light sins, without which we cannot live, prayer was instituted. . . . But do not commit those sins on account of which you would have to be separated from the body of Christ. Perish the thought! For those whom you see doing penance have committed crimes, either adultery or some other enormities. That is why they are doing penance. If their sins were light, daily prayer would suffice to blot them out. . . . In the Church, therefore, there are three ways in which sins are forgiven: in baptisms, in prayer, and in the greater humility of penance" (Sermon to Catechumens on the Creed 7:15, 8:16 [A.D. 395]).
Tradition
Tractate 6 (John 1:32-33)
"But in regard to those observances which we carefully attend and which the whole world keeps, and which derive not from Scripture but from Tradition, we are given to understand that they are recommended and ordained to be kept, either by the apostles themselves or by plenary [ecumenical] councils, the authority of which is quite vital in the Church" (Letter to Januarius [A.D. 400]).
Church is Catholic physically as well as spiritually
Tractate 6 (John 1:32-33)
"We must hold to the Christian religion and to communication in her Church, which is catholic and which is called catholic not only by her own members but even by all her enemies. For when heretics or the adherents of schisms talk about her, not among themselves but with strangers, willy-nilly they call her nothing else but Catholic. For they will not be understood unless they distinguish her by this name which the whole world employs in her regard" (The True Religion 7:12 [A.D. 390]).
Tractate 11 (John 2:23-3:5)
"We believe in the holy Church, that is, the Catholic Church; for heretics and schismatics call their own congregations churches. But heretics violate the faith itself by a false opinion about God; schismatics, however, withdraw from fraternal love by hostile separations, although they believe the same things we do. Consequently, neither heretics nor schismatics belong to the Catholic Church; not heretics, because the Church loves God, and not schismatics, because the Church loves neighbor" (Faith and Creed 10:21 [A.D. 393]).
Apostolic Succession
Against the Epistle of Manichaeus called Fundamental
"[T]here are many other things which most properly can keep me in [the Catholic Church's] bosom. The unanimity of peoples and nations keeps me here. Her authority, inaugurated in miracles, nourished by hope, augmented by love, and confirmed by her age, keeps me here. The succession of priests, from the very see of the apostle Peter, to whom the Lord, after his resurrection, gave the charge of feeding his sheep [John 21:15–17], up to the present episcopate, keeps me here. And last, the very name Catholic, which, not without reason, belongs to this Church alone, in the face of so many heretics, so much so that,
although all heretics want to be called 'Catholic,' when a stranger inquires where the Catholic Church meets, none of the heretics would dare to point out his own basilica or house" (Against the Letter of Mani Called "The Foundation" 4:5 [A.D. 397]).
Church Authority
The City of God (Book XXII)
"[On this matter of the Pelagians] two councils have already been sent to the Apostolic See [the bishop of Rome], and from there rescripts too have come. The matter is at an end; would that the error too might be at an end!" (Sermons 131:10 [A.D. 411]).
Communion of Saints
(Against Faustus the Manichean [A.D. 400] A Christian people celebrates together in religious solemnity the memorials of the martyrs, both to encourage their being imitated and so that it can share in their merits and be aided by their prayers.).
Deuterocanonical books
Tractate 124 (John 21:19-25) "The whole canon of the scriptures, however, in which we say that consideration is to be applied, is contained in these books: the five of Moses . . . and one book of Joshua [Son of] Nave, one of Judges; one little book which is called Ruth . . . then the four of Kingdoms, and the two of Paralipomenon . . . . [T]here are also others too, of a different order . . . such as Job and Tobit and Esther and Judith and the two books of Maccabees, and the two of Esdras . . . . Then there are the prophets, in which there is one book of the Psalms of David, and three of Solomon. . . . But as to those two books, one of which is entitled Wisdom and the other of which is entitled Ecclesiasticus and which are called 'of Solomon' because of a certain similarity to his books, it is held most certainly that they were written by Jesus Sirach. They must, however, be accounted among the prophetic books, because of the authority which is deservedly accredited to them" (Christian Instruction 2:8:13 [A.D. 397]).
The City of God (Book XXII)
"We read in the books of the Maccabees [2 Macc. 12:43] that sacrifice was offered for the dead. But even if it were found nowhere in the Old Testament writings, the authority of the Catholic Church which is clear on this point is of no small weight, where in the prayers of the priest poured forth to the Lord God at his altar the commendation of the dead has its place" (The Care to be Had for the Dead 1:3 [A.D. 421]).
Mary’s Immaculate Conception
Nature and Grace
"Having excepted the holy Virgin Mary, concerning whom, on account of the honor of the Lord, I wish to have absolutely no question when treating of sins—for how do we know what abundance of grace for the total overcoming of sin was conferred upon her, who merited to conceive and bear him in whom there was no sin?—so, I say, with the exception of the Virgin, if we could have gathered together all those holy men and women, when they were living here, and had asked them whether they were without sin, what do we suppose would have been their answer?" (Nature and Grace 36:42 [A.D. 415]).
Mary’s perpetual virginity
On Marriage and Concupiscence
when the holy bishop maintained the permanent virginity of the blessed Mary even after child-bearing, in opposition to this man's impiety. If, however, you do not dare to call him a Manichean, why do you call us Manicheans when we defend the catholic faith in the self-same cause and with the self same opinions?
Holy Virginity
"That one woman is both mother and virgin, not in spirit only but even in body. In spirit she is mother, not of our head, who is our Savior himself—of whom all, even she herself, are rightly called children of the bridegroom—but plainly she is the mother of us who are his members, because by love she has cooperated so that the faithful, who are the members of that head, might be born in the Church. In body, indeed, she is the Mother of that very head" (Holy Virginity 6:6 [A.D. 401]).
Mary the new Eve
Christian Combat
"Our Lord . . . was not averse to males, for he took the form of a male, nor to females, for of a female he was born. Besides, there is a great mystery here: that just as death comes to us through a woman, life is born to us through a woman; that the devil, defeated, would be tormented by each nature, feminine and masculine, as he had taken delight in the defection of both" (Christian Combat 22:24 [A.D. 396]).
Mortal and Venial Sins
The City of God (Book XXI)
"But those who do not belong to the number of the predestined . . . are judged most justly according to their deserts. For either they lie under sin which they contracted originally by their generation and go forth [from this life] with that hereditary debt which was not forgiven by regeneration [baptism], or [if it was forgiven by regeneration] they have added others besides through free choice: choice, I say, free; but not freed. . . . Or they receive God's grace, but they are temporal and do not persevere; they abandon it and are abandoned. For by free will, since they have not received the gift of perseverance, they are sent away in God's just and hidden judgment" (ibid.,13).
Purgatory
The City of God (Book XXII)
"But by the prayers of the holy Church, and by the salvific sacrifice, and by the alms which are given for their spirits, there is no doubt that the dead are aided, that the Lord might deal more mercifully with them than their sins would deserve. The whole Church observes this practice which was handed down by the Fathers: that it prays for those who have died in the communion of the Body and Blood of Christ, when they are commemorated in their own place in the sacrifice itself; and the sacrifice is offered also in memory of them, on their behalf. If, then, works of mercy are celebrated for the sake of those who are being remembered, who would hesitate to recommend them, on whose behalf prayers to God are not offered in vain? It is not at all to be doubted that such prayers are of profit to the dead; but for such of them as lived before their death in a way that makes it possible for these things to be useful to them after death" (ibid., 172:2).
The City of God (Book XXII)
"We read in the books of the Maccabees [2 Macc. 12:43] that sacrifice was offered for the dead. But even if it were found nowhere in the Old Testament writings, the authority of the Catholic Church which is clear on this point is of no small weight, where in the prayers of the priest poured forth to the Lord God at his altar the commendation of the dead has its place" (The Care to be Had for the Dead 1:3 [A.D. 421]).
Tractate 6 (John 1:32-33)
"That there should be some fire even after this life is not incredible, and it can be inquired into and either be discovered or left hidden whether some of the faithful may be saved, some more slowly and some more quickly in the greater or lesser degree in which they loved the good things that perish, through a certain purgatorial fire" (Handbook on Faith, Hope, and Charity 18:69 [A.D. 421]).
Tractate 49 (John 11:1-54)
"The time which interposes between the death of a man and the final resurrection holds souls in hidden retreats, accordingly as each is deserving of rest or of hardship, in view of what it merited when it was living in the flesh. Nor can it be denied that the souls of the dead find relief through the piety of their friends and relatives who are still alive, when the Sacrifice of the Mediator [Mass] is offered for them, or when alms are given in the Church. But these things are of profit to those who, when they were alive, merited that they might afterward be able to be helped by these things. There is a certain manner of living, neither so good that there is no need of these helps after death, nor yet so wicked that these helps are of no avail after death" (ibid., 29:109).
