The question is where the Church should be. ... What then shall we do? Shall we seek it in our words, or in the words of our Lord Jesus? In my judgment we ought rather to seek the Church in His own words, for that He is the Truth, and knoweth His own body.- Augustine, On the Unity of the Church, Chapter 2, §2.
The question between us and the Donatists is, Where is the Church to be found ? What then shall we do ? Shall we seek it in our words, or in the words of its head, our Lord Jesus Christ ? I conceive that we ought to seek it in His words, who is the truth, and best knows His own body.- Augustine, On the Unity of the Church, Chapter 2, §2.
Let us not hear, You say this, I say that; but let us hear Thus saith the Lord. There are the Dominical books, whose authority we both acknowledge, we both yield to, we both obey; there let us seek the Church, there let us discuss the question between us.- Augustine, On the Unity of the Church, Chapter 3, §5.
Therefore let those testimonies which we mutually bring against each other, from any other quarter than the divine canonical books, be put out of sight.- Augustine, On the Unity of the Church, Chapter 3, §5.
Longer alternative translation vis-a-vis 1&2:
Let not these words be heard between us, "I say," or "You say," but rather let us hear, "Thus saith the Lord;" for there are certain books of our Lord on whose authority both sides acquiesce; there let us seek our Church, there let us judge our cause. Take away, therefore, all those things which each alleges against the other, and which are derived from other sources than the canonical books of the Holy Scriptures. But, perhaps, some will ask, "Why take away such authorities?" Because I would have the Holy Church proved, not by human documents, but by the Word of God.- Augustine, On the Unity of the Church, Chapter 3, §5.
I would not have the holy Church demonstrated by human testimonies, but by divine oracles.- Augustine, On the Unity of the Church, Chapter 3, §6.
Whatever they may adduce, and wherever they may quote from, let us rather, if we are His sheep, hear the voice of our Shepherd. Therefore let us search for the church in the sacred canonical Scriptures.- Augustine, On the Unity of the Church, Chapter 3, §6. (This comes shortly after the above, but the translation seems a little loose.)
Whoever dissents from the sacred Scriptures, even if they are found in all places in which the church is designated, are not the church.- Augustine, On the Unity of the Church, Chapter 4, §7.
We adhere to this Church; against those divine declarations we admit no human cavils.- Augustine, On the Unity of the Church, Chapter 11, §28.
I have the most manifest voice of my pastor commending to me, and without any hesitation setting forth the church, I will impute it to myself, if I shall wish to be seduced by the words of men and to wander from his flock, which is the church itself, since he specially admonished me saying, My sheep hear my voice and follow me; listen to his voice clear and open and heard; who does not follow, how will he dare to call himself his sheep? Let no one say to me, What hath Donatus said, what hath Parmenian said, or Pontius, or any of them. For we must not allow even Catholic bishops, if at any time, perchance, they are in error, to hold any opinion contrary to the Canonical Scriptures of God.- Augustine, On the Unity of the Church, Chapter 11, §28.
Alternative Partial Translation:
Neither dare one agree with catholic bishops if by chance they err in anything, but the result that their opinion is against the canonical Scriptures of God.- Augustine, On the Unity of the Church, Chapter 11, §28.
Alternative Partial Translation:
either must we agree with Catholic Bishops, if they err, or decide anything against God's canonical Scriptures.- Augustine, On the Unity of the Church, Chapter 11, §28.
All such matters, therefore, being put out of sight, let them show their Church, if they can; not in the discourses and reports of Africans, not in the councils of their own bishops, not in the writings of any controversialists, not in fallacious signs and miracles, for even against these we are rendered by the word of the Lord prepared and cautious, but in the ordinances of the Law, in the predictions of the Prophets, in the songs of the Psalms, in the words of the very Shepherd himself, in the preachings and labours of the Evangelists, that is, in all the canonical authorities of sacred books. Nor so as to collect together and rehearse those things that are spoken obscurely, or ambiguously, or figuratively, such as each can interpret as he likes, according to his own views. For such testimonies cannot be rightly understood and expounded, unless those things that are most clearly spoken are first held by a firm faith.- Augustine, On the Unity of the Church, Chapter 18, §47.
Alternative partial translation:
Let them show their church if they can, not by the speeches and mumblings of the Africans, not by the councils of their bishops, not by the writings of any of their champions, not by fraudulent signs and wonders, because we have been prepared and made cautious also against these things by the Word of the Lord; but [let them show their church] by a command of the Law, by the predictions of the prophets, by songs from the Psalms, by the words of the Shepherd Himself, by the preaching and labors of the evangelists; that is, by all the canonical authorities of the sacred books.- Augustine, On the Unity of the Church, Chapter 18, §47.
Alternative partial translation:
Let the Donatists, if they can, show their Church, not in the rumours and speeches of the men of Africa, not in the councils of their Bishops, not in the discourses of any writers whatever, not in signs and miracles that may be forged, for we are forewarned by God's word, and therefore forearmed, against those things; but in the prescript of the law, in the predictions of the Prophets, in the verses of the Psalms, in the voice of the Shepherd himself, in the preachings and writings of the Evangelists, that are in all the canonical authorities of the sacred Scriptures.- Augustine, On the Unity of the Church, Chapter 18, §47.
Alternative longer translation:
Benounce, therefore all such things, and show your Church, if you can, not in the sayings of Africa, not in the Councils of your Bishops, not in signs and lying wonders, but in the writings of the Law, the predictions of the Prophets, in the Psalms, in the words of the Shepherd Himself, in the preaching and labours of the Apostles—that is, by the authority of all books of the Canonical Scriptures. For we do not say that we ought to be believed because we are in the Church of Christ, or because that Church to which we belong, was commended to us by Optatus, Ambrose, or other innumerable Bishops of our communion; or because miracles are everywhere wrought in it. These things are indeed to be approved, because they are done in the Catholic Church, but it is not thence proved to be the Catholic Church, because such things are done in it. Our Lord Jesus Christ Himself, when He rose from the dead, and offered His body to be touched as well as seen by His disciples, lest there should be any fallacy in it, thought it proper to convince them, rather by the testimony of the Law, the Prophets, and the Psalms, showing how all things were fulfilled which had been foretold; and so He commanded His Church, saying, that repentance and remission of sins should be preached in His Name, among all nations, beginning at Jerusalem. This He testified was written in the Law, the Prophets, and the Psalms; this we hold, as commended from His mouth. These are the documents, these the foundations, these the strong grounds of our cause. We read in the Acts of the Apostles, of some believers, that they daily searched the Scriptures if these things were so. What Scriptures ? but the canonical books of the Law and the Prophets; to which are added the Gospels, the Apostolical Epistles, the Acts of the Apostles, and the Revelation of St. John. Search, then, all these, and bring forth something manifest, by which you may prove the Church to have remained only in Africa, or come out of Africa.- Augustine, On the Unity of the Church, Chapter 18, §47.
We ought to find the Church, as the Head of the Church, in the Holy Canonical Scriptures, not to inquire for it in the various reports, and opinions, and deeds, and words, and visions of men.- Augustine, On the Unity of the Church, Chapter 19, §49.
Whether they [i.e. the Donatists] hold the Church, they must show by the Canonical books of the Divine Scriptures alone; for we do not say, that we must be believed because we are in the Church of Christ, because Optatus of Milevi, or Ambrose of Milan, or innumerable other bishops of our communion, commended that Church to which we belong, or because it is extolled by the Councils of our colleagues, or because through the whole world in the holy places which those of our communion frequent such wonderful answers to prayers or cures happen.- Augustine, On the Unity of the Church, Chapter 19, §50.
Whatever things of this kind take place in the Catholic Church, are therefore to be approved of because they take place in the Catholic Church; but it is not proved to be the Catholic Church, because these things happen in it. The Lord Jesus himself when he had risen from the dead . . . judged that his disciples were to be convinced by the testimonies of the Law and the Prophets and the Psalms . . . These are the proofs, these the foundations, these the supports for our cause. We read in the Acts of the Apostles of some who believed, that they searched the Scriptures daily, whether these things were so. What Scriptures but the Canonical Scriptures of the Law and the Prophets? To these have been added the Gospels, the Apostolical Epistles, the Acts of the Apostles, the Apocalypse of John.- Augustine, On the Unity of the Church, Chapter 19, §50-51.
But if they do not choose to understand, it is sufficient for us that we adhere to that Church which is demonstrated by such extremely clear testimonies of the Holy and Canonical Scriptures.- Augustine, On the Unity of the Church, Chapter 19, §50-51.