Question: You strongly hold to the principle of Sola Scriptura. This teaching is relatively new, it cannot be found anywhere in the history of Christendom until the Protestant reformation in the 16^th Century. I would deeply appreciate if you could show me why you would believe such an erroneous teaching.

Answer: The principle of Sola Scriptura - the Holy Scripture is the only infallible rule of faith for the church - is neither new nor erroneous. On the contrary, the Church Fathers testify that they too upheld the Scriptures as the sufficient and authoritative font of divine revelation.

The Fathers also held tradition in high esteem, but for them tradition was not a supplementary source of divine doctrines in addition to the teaching of the Scripture. Historian Philip Schaff explains:

“Besides appealing to the Scriptures, the fathers, particularly Irenaeus and Tertullian, refer with equal confidence to the "rule of faith;" that is, the common faith of the church, as orally handed down in the unbroken succession of bishops from Christ and his apostles to their day, and above all as still living in the original apostolic churches, like those of Jerusalem, Antioch, Ephesus, and Rome… the substance of its doctrine this apostolic tradition agrees with the holy scriptures, and though derived, as to its form, from the oral preaching of the apostles, is really, as to its contents, one and the same with their apostolic writings… In the narrower sense, by apostolic tradition or the rule of faith was understood a doctrinal summary of Christianity, or a compend of the faith of the church.” History of the Christian Church, II:12.

The following quotations prove that the Fathers considered the Scriptures as both sufficient and the highest authority in the church.

Irenaeus, Against Heresies, Book III.

We have learned from none others the plan of our salvation, than from those through whom the Gospel has come down to us, which they did at one time proclaim in public, and, at a later period, by the will of God, handed down to us in the Scriptures, to be the ground and pillar of our faith. 

Athanasius; Against the Heathen, I:3.

The holy and inspired Scriptures are fully sufficient for the proclamation of the truth. 

Athanasius, De Synodis.

Vainly then do they run about with the pretext that they have demanded Councils for the faith's sake; for divine Scripture is sufficient above all things; but if a Council be needed on the point, there are the proceedings of the Fathers, for the Nicene Bishops did not neglect this matter, but stated the doctrine so exactly, that persons reading their words honestly, cannot but be reminded by them of the religion towards Christ announced in divine Scripture. 

John Chrysostom, Homily 8 On Repentance and the Church, p. 118, vol. 96 TFOTC.

Regarding the things I say, I should supply even the proofs, so I will not seem to rely on my own opinions, but rather, prove them with Scripture, so that the matter will remain certain and steadfast. 

Gregory of Nyssa, On the Holy Trinity.

For if custom is to avail for proof of soundness, we too, surely, may advance our prevailing custom; and if they reject this, we are surely not bound to follow theirs. Let the inspired Scripture, then, be our umpire, and the vote of truth will surely be given to those whose dogmas are found to agree with the Divine words. 

Gregory of Nyssa, On the Soul and the Resurrection.

We are not entitled to such licence, I mean that of affirming what we please; we make the Holy Scriptures the rule and the measure of every tenet; we necessarily fix our eyes upon that, and approve that alone which may be made to harmonize with the intention of those writings.

Basil, The Morals, p. 204, vol 9 TFOTC

What is the mark of a faithful soul? To be in these dispositions of full acceptance on the authority of the words of Scripture, not venturing to reject anything nor making additions. For, if ‘all that is not of faith is sin’ as the Apostle says, and ‘faith cometh by hearing and hearing by the Word of God,’ everything outside Holy Scripture, not being of faith, is sin.

Basil, On the Holy Spirit, 7.

We are not content simply because this is the tradition of the Fathers. What is important is that the Fathers followed the meaning of the Scripture.

Basil, Moralia, 72:1.

The hearers taught in the Scriptures ought to test what is said by teachers and accept that which agrees with the Scriptures but reject that which is foreign. 

Augustine, Contra litteras Petiliani, Bk 3, ch. 6.

If anyone preaches either concerning Christ or concerning His church or concerning any other matter which pertains to our faith and life; I will not say, if we, but what Paul adds, if an angel from heaven should preach to you anything besides what you have received in the Scriptures of the Law and of the Gospels, let him be anathema.

Cyril of Jerusalem, Catechetical Lectures, IV:17.

For concerning the divine and holy mysteries of the Faith, not even a casual statement must be delivered without the Holy Scriptures; nor must we be drawn aside by mere plausibility and artifices of speech. Even to me, who tell you these things, give not absolute credence, unless you receive the proof of the things which I announce from the Divine Scriptures. For this salvation which we believe depends not on ingenious reasoning, but on demonstration of the Holy Scriptures.

Augustine, De Unitate Ecclesiae, 10.

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, De Unitate Ecclesiae, 3.

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 Christian Doctrine, II, 9.

For among the things that are plainly laid down in Scripture are to be found all matters that concern faith and the manner of life. 

Augustine, De Bono Viduitatis.

What more shall I teach you than what we read in the apostles? For Holy Scripture fixes the rule for our doctrine, lest we dare be wiser than we ought. Therefore I should not teach you anything else except to expound to you the words of the Teacher.

Hippolytus, Against the Heresy of One Noetus, 9.

There is, brethren, one God, the knowledge of whom we gain from the Holy Scriptures, and from no other source… so all of us who wish to practice piety will be unable to learn its practice from any other quarter than the oracles of God. Whatever things, then, the Holy Scriptures declare, at these let us look; and whatever things they teach, these let us learn.