The Early Church Fathers were Catholic
Ignatius of Antioch - on the Catholic Church - Follow your bishop, every one of you, as obediently as Jesus Christ followed the Father. Obey your clergy too as you would the apostles; give your deacons the same reverence that you would to a command of God. Make sure that no step affecting the Church is ever taken by anyone without the bishop’s sanction. The sole Eucharist you should consider valid is one that is celebrated by the bishop himself, or by some person authorized by him. Where the bishop is to be seen, there let all his people be; just as, wherever Jesus Christ is present, there is the Catholic Church (Letter to the Smyrnaeans 8:2 [A.D. 110]).
Papias - on Oral Tradition - Whenever anyone came my way, who had been a follower of my seniors, I would ask for the accounts of our seniors: What did Andrew or Peter say? Or Phillip or Thomas or James or John or Matthew, or any of the Lord’s disciples? I also asked: What did Aristion and John the Presbyter, disciples of the Lord say. For, as I see it, it is not so much from books as from the living and permanent voice that I must draw profit (The Sayings of the Lord [between A.D. 115 and 140] as recorded by Eusebius, Ecclesiastical History, 3:39 [A.D. 325]).
Irenaeus - on Church Authority and Tradition - For even creation reveals Him who formed it, and the very work made suggests Him who made it, and the world manifests Him who ordered it. The Universal [Catholic] Church, moreover, through the whole world, has received this tradition from the Apostles (Against Heresies 2:9 [A.D. 189]). True knowledge is the doctrine of the Apostles, and the ancient constitution of the Church throughout all the world, and the distinctive manifestation of the body of Christ according to the successions of the bishops, by which they have handed down that Church which exists in every place, and has come even unto us, being guarded and preserved, without any forging of Scriptures, by a very complete system of doctrine, and neither addition nor curtailment … (ibid. 4:33 [A.D. 189]).
Tertullian - on Tradition - For wherever both the true Christian rule and faith shall be shown to be, there will be the true Scriptures, and the true expositions, of all the true Christian traditions (The Prescription of Heretics 19 [A.D. 200]).
Athanasius - on Church Authority and Tradition - Without prefixing Consulate, month, and day, [the Fathers] wrote concerning Easter, "It seemed good as follows," for it did then seem good that there should be a general compliance; but about the faith they wrote not, "It seemed good" but, "Thus believes the Catholic Church"; and thereupon they confessed how they believed, in order to show that their own sentiments were not novel, but Apostolic; and what they wrote down was no discovery of theirs, but is the same as was taught by the Apostles (Letter on the Councils of Ariminum and Seleucia [A.D. 359]).
Jerome - on Tradition - Don’t you know that the laying on of hands after baptism and then the invocation of the Holy Spirit is a custom of the Churches? Do you demand Scripture proof? You may find it in the Acts of the Apostles. And even if it did not rest on the authority of Scripture the consensus of the whole world in this respect would have the force of a command. For many other observances of the Churches, which are do to tradition, have acquired the authority of the written law (The Dialogue Against the Luciferians 8 [A.D. 382]). John Chrysostom - on Oral Tradition - "So then brethren, stand fast, and hold the traditions which you were taught, whether by word, or by epistle of ours" (2 Thessalonians 2:15). Hence it is manifest, that they did not deliver all things by epistle, but many things also unwritten, and in like manner both the one and the other are worthy of credit. Therefore let us think the tradition of the Church also worthy of credit. It is a tradition, seek no farther (Homilies on Second Thessalonians [circa A.D. 400]).
Augustine - on Church Authority - "Number the priests even from that seat of Peter. And in that order of fathers see to whom succeeded: that is the rock which the proud gates of hades do not conquer."
“You see, there have already been two councils about this matter, and their decisions sent to the Apostolic [Roman] See; from there rescripts have been sent back here. The case is finished; if only the error were finished too, sometime! So, let us all warn them to take notice of this, teach them to learn the lesson of it, pray for them to change their ideas."
“For my part, I should not believe the gospel except moved by the authority of the Catholic Church. So when those on whose authority I have consented to believe in the gospel tell me not to believe in Manicheus, how can I but consent?"
It must also be noted that statements and teachings of the Early Church Fathers on Mary are in complete harmony with the Catholic teachings of today, which are in complete harmony with Scripture. If these men (some of whom shed their blood for the faith), who kept the faith alive after the Apostolic era, were teaching heresy and a fraudulent Christianity, then 21st Century Protestants must ask themselves: What was their motive for doing so? Why were they willing to die for these beliefs if they were not the truth?” Didn’t Jesus promise that the gates of hell wouldn’t prevail against his Church (Matt. 16:18)? Simply put, to believe that the Church was apostate until the Reformation is to render our Lord and Savior a liar.