David T. King, a Reformed Protestant pastor and apologist, made the following extraordinary statement in his self-published book, Holy Scripture: The Ground and Pillar of Our Faith:

No Church father believed the Church as a whole to be infallible. The opinion was that individual bishops, as well as bishops in Council, could err. It is our contention that the early Church fathers, with unanimous voice, point us back to holy Scripture as the only infallible norm.

I shall now prove the massive falsehood of this claim. The Church Fathers thought the Church was infallible and indefectible:

• St. Irenaeus: Wherefore it is incumbent to obey the presbyters who are in the Church — those who, as I have shown, possess the succession from the apostles; those who, together with the succession of the episcopate, have received the certain [or infallible] gift of truth [charisma veritatis certum], according to the good pleasure of the Father. (Against Heresies, 4, 26, 2)
• St. Clement of Alexandria: So also are we bound in no way to transgress the canon of the Church. … In the truth alone and in the ancient Church is both the most exact knowledge, and the truly best set of principles (airesis). (Stromata, VII, 15)
• St. Hippolytus: Patristics scholar Johannes Quasten describes his view:

Throughout his refutation of heresy, he purposes to prove the Church the bearer of truth and the apostolic succession of the bishops the guarantee of her teaching. (Patrology, four volumes, Vol. II: The Ante-Nicene Literature after Irenaeus, Allen, Texas: Christian Classics; division of Thomas More Publishing, no date, p. 202)

• St. Cyprian: The Church herself also is uncorrupted … (Epistle 72: To Jubaianus, 11)
• Tertullian: All doctrine must be prejudged as false which savors of contrariety to the truth of the churches and apostles of Christ and God. (The Prescription Against Heretics, chapter 21)
• Origen: As the teaching of the Church, transmitted in orderly succession from the apostles, and remaining in the Churches to the present day, is still preserved, that alone is to be accepted as truth which differs in no respect from ecclesiastical and apostolical tradition. (De Principiis, preface, complete section 2)
• St. Athanasius: It is enough merely to answer such things as follows: we are content with the fact that this is not the teaching of the Catholic Church, nor did the Fathers hold this. (Letter No. 59 to Epictetus, 3)
• St. Ambrose: Seeing, therefore, that men who agree not among themselves have all alike conspired against the Church of God, I shall call those whom I have to answer by the common name of heretics. (Exposition of the Christian Faith, Bk. I, chapter 6, section 46)
• St. Augustine: It is obvious; the faith allows it; the Catholic Church approves; it is true. (Sermon 117, 6)
• St. Cyril of Alexandria: The Church, having Christ for a foundation, and an immovable support, is perfectly immovable. (Commentary on Isaiah, 4)

The eminent Protestant Church historian Philip Schaff (History of the Christian Church) describes the perspective of the Ante-Nicene Fathers: 

No heresy can reach the conception of the church … the church is divine and indestructible. This is without doubt the view of the ante-Nicene fathers, even of the speculative and spiritualistic Alexandrians …

And they affirmed the infallibility of ecumenical councils:

• St. Cyprian: Although long since it was decreed, in a council of the bishops ... (Epistle 65, 1)
• St. Basil the Great: You should confess the faith put forth by our Fathers once assembled at Nicæa, that you should not omit any one of its propositions, but bear in mind that the 318 who met together without strife did not speak without the operation of the Holy Ghost ... (Letter 114 to Cyriacus, at Tarsus)
• St. Gregory Nazianzen: I never have and never can honor anything above the Nicene Faith, that of the Holy Fathers who met there to destroy the Arian heresy; but am, and by God’s help ever will be, of that faith ... (Letter 102: Second to Cledonius the Priest, Against Apollinarius)
• St. Ambrose: Of the Acts of Councils, I shall let that one be my chief guide which 318 priests [at the Council of Nicaea], appointed, as it were, after the judgment of Abraham, made (so to speak) a trophy raised to proclaim their victory over the infidel throughout the world, prevailing by that courage of the Faith, wherein all agreed. Verily, as it seems to me, one may herein see the hand of God ... (Exposition of the Christian Faith, Bk. I, Prologue, section 5)
• St. Athanasius: Who will not denounce their audacity ... [who] would forcibly cancel the decrees of an uncorrupt, pure and Ecumenical Council? (Ad Episcopos Aegypti et Libyae, 7)
• St. Cyril of Alexandria: He opposes the truth and the very symbol of the Church’s faith, which the Fathers once gathered together at Nicaea through the illumination of the Spirit defined; he, fearing lest any should keep whole the Faith, instructed unto the truth by their words, endeavors to calumniate it and alters the significance of the words ... against the holy Fathers who have decreed for us the pious definition of the Faith which we have as an anchor of the soul both sure and steadfast, as it is written. (Tomes Against Nestorius: I, 5)
• St. Cyril of Alexandria: The holy Churches in every region under Heaven, and the venerable Fathers themselves who put forth unto us the definition of the right and undefiled Faith, viz. (the Holy Ghost speaking in them) that the Word of God was made flesh and became Man ... (Tomes Against Nestorius: IV, 2)