Advocates for sola scriptura argue that Christians need a written record since oral tradition is so given to inaccuracies and therefore untrustworthy. Aside from the fact that anthropological studies have demonstrated the extremely accurate fidelity of oral traditions in cultures for whom such traditions are central to their culture (unlike literate cultures such as ours), there is a very accessible way to demonstrate both the accuracy and trustworthiness of the oral apostolic tradition.
If one were to compare contemporary Christian writers, who were separated by significant geographical distance, and were writing before the full canonization of the Christian Scriptures, and even during the period when there was some dispute over which books were Scripture, and also during the period when many heresies had arisen, and if those writers provided a summary of the Christian faith, then one can readily compare whether or not the oral apostolic tradition is accurate and trustworthy. As St. Irenaeus of Lyon writes:
As I have already observed, the Church, having received this preaching and this faith, although scattered throughout the whole world, yet, as if occupying but one house, carefully preserves it. She also believes these points (of doctrine) just as if she had but one soul, and one and the same heart, and she proclaims them, and teaches them, and hands them down, with perfect harmony, as if she possessed only one mouth. For, although the languages of the world are dissimilar, yet the import of the tradition is one and the same. For the Churches which have been planted in Germany do not believe or hand down anything different, nor do those in Spain, nor those in Gaul, nor those in the East, nor those in Egypt, nor those in Libya, nor those which have been established in the central regions of the world. But as the sun, that creature of God, is one and the same throughout the whole world, so also the preaching of the truth shineth everywhere, and enlightens all men that are willing to come to a knowledge of the truth. Nor will any one of the rulers in the Churches, however highly gifted he may be in point of eloquence, teach doctrines different from these (for no one is greater than the Master); nor, on the other hand, will he who is deficient in power of expression inflict injury on the tradition. For the faith being ever one and the same, neither does one who is able at great length to discourse regarding it, make any addition to it, nor does one, who can say but little diminish it.(St. Irenaeus of Lyons, Against Heresies, Bk I, Ch. X, Par. 2)
Now, the historical period that would be ideal, in my view, would be the end of the second century, or beginning of the third. My reasons that this period would be ideal are these:
1. Although all of the New Testament books had been written, historical evidence indicates that not only did not all Christian communities have all of the New Testament books, but that some considered certain books divinely authoritative that others did not, some of which in fact did make it into the New Testament canon (e. g., Revelation) and some of which in fact did not (e. g., Shepherd of Hermas). Thus, given these canonical discrepancies, it would be theoretically possible for there to be equally discrepant practices and beliefs among these far-flung contemporary Christian groups.
2. Furthermore, given 1, there would need to be a great reliance on oral apostolic tradition, all the more so, if, as scholars generally assume, the vast majority of Christians at the end of the second century (and generally throughout history) were illiterate and entirely dependent on oral tradition.
3. Thus, given 1 and 2, if oral tradition is inaccurate and untrustworthy, if one selects contemporary communities in geographically distant locales, it would stand to reason that there would potentially be great discrepancies among the central beliefs that they hold.
I will demonstrate that 3 is false, and that therefore the claim by sola scriptura advocates that oral tradition is unreliable is unfounded.
My three representative writers will be St. Irenaeus of Lyons, in western Europe; Tertullian of Carthage in northern Africa; and Origen of Alexandria, also in northern Africa to the west of Carthage. Lyons is definitely significantly geographically distant from northern Africa, though Alexandria and Carthage are near enough to be geographically linked via trade routes. Furthermore, Alexandria was well known for number of Christian heresies arising from teachers resident there. Indeed, certain doctrines espoused by Origen were later condemned by ecumenical council. And Tertullian himself later embraced the sectarian heresy of Montanism. So this should be enough thrown in the mix to give one a reason to think there would be great discrepancy in the faith of these three men.
Since St. Irenaeus can be considered an orthodox standard against which to judge the others, I will cite him first.
The Church, though dispersed through our the whole world, even to the ends of the earth, has received from the apostles and their disciples this faith: (She believes) in one God, the Father Almighty, Maker of heaven, and earth, and the sea, and all things that are in them; and in one Christ Jesus, the Son of God, who became incarnate for our salvation; and in the Holy Spirit, who proclaimed through the prophets the dispensations of God, and the advents, and the birth from a virgin, and the passion, and the resurrection from the dead, and the ascension into heaven in the flesh of the beloved Christ Jesus, our Lord, and His (future) manifestation from heaven in the glory of the Father “to gather all things in one,” [Ephesians 1:10] and to raise up anew all flesh of the whole human race, in order that to Christ Jesus, our Lord, and God, and Saviour, and King, according to the will of the invisible Father, “every knee should bow, of things in heaven, and things in earth, and things under the earth, and that every tongue should confess” [Philippians 2:10-11] to Him, and that He should execute just judgment towards all; that He may send “spiritual wickednesses,” [Ephesians 6:12] and the angels who transgressed and became apostates, together with the ungodly, and unrighteous, and wicked, and profane among men, into everlasting fire; but may, in the exercise of His grace, confer immortality on the righteous, and holy, and those who have kept His commandments, and have persevered in His love, some from the beginning (of their Christian course), and others from (the date of) their repentance, and may surround them with everlasting glory.(St. Irenaeus of Lyons, Against Heresies, Bk I, Ch. X, Par. 1)
Next, let’s look at Tertullian, who later abandoned the faith.
Now, with regard to this rule of faith-that we may from this point acknowledge what it is which we defend-it is, you must know, that which prescribes the belief that there is one only God, and that He is none other than the Creator of the world, who produced all things out of nothing through His own Word, first of all sent forth; that this Word is called His Son, and, under the name of God, was seen “in diverse manners” by the patriarchs, heard at all times in the prophets, at last brought down by the Spirit and Power of the Father into the Virgin Mary, was made flesh in her womb, and, being born of her, went forth as Jesus Christ; thenceforth He preached the new law and the new promise of the kingdom of heaven, worked miracles; having been crucified, He rose again the third day; (then) having ascended into the heavens, He sat at the right hand of the Father; sent instead of Himself the Power of the Holy Ghost to lead such as believe; will come with glory to take the saints to the enjoyment of everlasting life and of the heavenly promises, and to condemn the wicked to everlasting fire, after the resurrection of both these classes shall have happened, together with the restoration of their flesh. This rule, as it will be proved, was taught by Christ, and raises amongst ourselves no other questions than those which heresies introduce, and which make men heretics. (Tertullian, Prescription Against Heretics, Ch. 13)
And finally, Origen, who, although some of his doctrines were later condemned, was nontheless a significant influence on orthodox Christian writers such as St. Maximus the Confessor.
The particular points clearly delivered in the teaching of the apostles are as follow:-
First, That there is one God, who created and arranged all things, and who, when nothing existed, called all things into being-God from the first creation and foundation of the world-the God of all just men, of Adam, Abel, Seth, Enos, Enoch, Noe, Sere, Abraham, Isaac, Jacob, the twelve patriarchs, Moses, and the prophets; and that this God in the last days, as He had announced beforehand by His prophets, sent our Lord Jesus Christ to call in the first place Israel to Himself, and in the second place the Gentiles, after the unfaithfulness of the people of Israel. This just and good God, the Father of our Lord Jesus Christ, Himself gave the law and the prophets, and the Gospels, being also the God of the apostles and of the Old and New Testaments.
Secondly, That Jesus Christ Himself, who came (into the world), was born of the Father before all creatures; that, after He had been the servant of the Father in the creation of all things-“For by Him were all things made” [John 1:3]-He in the last times, divesting Himself (of His glory), became a man, and was incarnate although God, and while made a man remained the God which He was; that He assumed a body like to our own, differing in this respect only, that it was born of a virgin and of the Holy Spirit: that this Jesus Christ was truly born, and did truly suffer, and did not endure this death common (to man) in appearance only, but did truly die; that He did truly rise from the dead; and that after His resurrection He conversed with His disciples, and was taken up (into heaven).
Then, Thirdly, the apostles related that the Holy Spirit was associated in honour and dignity with the Father and the Son. But in His case it is not clearly distinguished whether He is to be regarded as born or innate, or also as a Son of God or not: for these are points which have to be inquired into out of sacred Scripture according to the best of our ability, and which demand careful investigation. And that this Spirit inspired each one of the saints, whether prophets or apostles; and that there was not one Spirit in the men of the old dispensation, and another in those who were inspired at the advent of Christ, is most clearly taught throughout the Churches.
After these points, also, the apostolic teaching is that the soul, having a substance and life of its own, shall, after its departure from the world, be rewarded according to its deserts, being destined to obtain either an inheritance of eternal life and blessedness, if its actions shall have procured this for it, or to be delivered up to eternal fire and punishments, if the guilt of its crimes shall have brought it down to this: and also, that there is to be a time of resurrection from the dead, when this body, which now “is sown in corruption, shall rise in incorruption,” and that which “is sown in dishonour will rise in glory.”[1 Corinthians 15:42-43](Origen, De Principiis, Preface, Pars. 4-5)
One can easily note the striking similarity on doctrinal points as well as verbal formulations (even in translation, and from different original languages) of these three writers.
All that remains is to juxtapose these teachings against the Scriptures to note, even on sola scriptura terms, the apostolic origin of these teachings, and therefore their divine authority.
Now, let me readily admit that my stress on the oral apostolic tradition might well be compromised by the following facts.
1. All three of my representatives are literate, indeed, Origen is recognized as a brilliant genius. These men themselves were not dependent wholly on oral tradition for their summations, but could recall those apostolic writings they had themselves read.
2. St. Irenaeus and Origen both cite Scripture directly, thereby demonstrating that they relied on the apostolic writings.
These facts would seem to obviate my claims that oral apostolic tradition was both accurate and trustworthy, for it seems clear that these men were not using oral apostolic tradition but the apostolic writings themselves.
But here’s why such facts do not, contrary to my sola scriptura interlocutors, obviate my claims for the accuracy and trustworthiness of the oral apostolic tradition.
These men are offering summations of the faith, which requires not merely the direct reliance on Scripture, but an interpretive framework by which they can select and emphasize those different texts (and they use different texts to make the same points). Furthermore, which books were deemed Scripture was itself not always a certainty, and this required some sort of incipient canon handed down through oral apostolic tradition. That the Gnostic heretics in Alexandria emphasized different canonical and non-canonical texts, and interpreted them in a vastly different way from our writers is both obvious and evidence that our writers were not just operating from private interpretations but from a tradition that they themselves had received.
Now, it may well be that some other explanation(s) than oral apostolic tradition accounts for this consonance, but it’s hard to know what that could be. One could not appeal to private interpretation, for that would be belied by the heresies that also arose from private interpretation. One could suppose that God worked directly on the minds of these men in separate locales to sum up the faith just in the way they did, but one wonders how this differs in essence from direct inspiration, and one is also hard pressed to justify that explanation in the face of Origen’s heresies, and Tertullian’s later abadonment of the faith. One also wonders why such direct inspiration is not more readily at work today, given the increasing discrepancies among Christian bodies to sum up the faith.
No, given the facts, the best explanation which does not involve special pleading (direct inspiration) or manifest contradiction (private interpretation) is going to be that these men relied on the oral apostolic tradition, which had been faithfully and carefully transmitted throughout out varying geographical, religious and cultural locales.
Thus, oral apostolic tradition is accurate and trustworthy, and the fact that Scripture itself commands us to attend to both oral and written apostolic tradition (2 Thessalonians 2:15) is enough to bolster this contention on its own in sola scriptura terms.
*Please note that I am indebted for my references to St. Irenaeus, Origen and Tertullian above in a passing reference by Eric Jay in his article “From Presbyter-Bishops to Bishops and Presbyters.”