George Florovsky (1893-1979), 'The Authority of the Ancient Councils and the Tradition of the Fathers', in Glaube, Geist, Geschichte: Festschrift fur Ernst Benz (Leiden: Brill, 1967, pp177-88).
Sola Scriptura is at its core the confession that the Scriptures are sufficient for both the individual and for the faith and life of the Church to which the individual Christian belongs by baptism. There are those who try to make this into a competition with tradition but that betrays the intention of the Reformers who insisted that what the Scriptures taught was not a message that changed or developed or evolved the but one consistent truth. Tradition has its source in Scripture and grew up around the Scriptures as the faithful confession of generations who heard and believed the Word of the Lord. The authority of tradition was not separate or distinct from Scripture but flowed from Scripture itself. Scripture normed this tradition just as it norms the community of those who have been called into Christ's life through it, bidden to the waters of baptism where, by death and resurrection, they were born anew. It is foolishness to speak of Scripture as naked or apart from the faithful community that Scripture's voice has gathered and always will gather. The Word is not something we have in theory but the practical Word that is efficacious as well as true. We need no further nor distinct revelation apart from Christ and from the Scriptures which speak of Him (promise and fulfillment).
At Christmas this truth is even more clearly attested. In many and various ways God spoke to His people of old but now He has spoken through His Son. Just as Christ is sufficient, His sufferings need no addition nor does His righteousness lack anything, so the Word is sufficient. It conveys what it promises and when it speaks, it does what it says. To speak of Sola Scriptura is to speak of Christ's own sufficiency as Savior and Redeemer, of Prophet, Priest, and King. Such should not have been a sticking point with Rome. The Church has always confessed the sufficiency of Christ's merits to win salvation for us. When we confess Sola Scriptura we are making a parallel claim and confession.
Florovsky recognized this claim of the Reformation as a catholic claim, one known well in the early Church and one which every orthodox community of Christians has known, acknowledged, and confessed. Lutherans stand within the great catholic faith when we confess this. We show no disdain for tradition -- only for its misuse which attempts to set tradition apart from the Word that gave it its birth and still gives it its life. St. Paul wrote of this sacred deposit, of the good tradition, of the faith once delivered to the saints. Yet, somehow, we find ourselves discontented with Paul's affirmation. On the one hand we have attempted to strip Scripture away from the community which the Word itself gathers and calls into being (Protestant) and on the other hand we have attempted to set up tradition as if it were an authority of equal weight and stature apart from Scripture. When we do either, we fall victim to the great tendency to define separately what belongs together and has always been together.
In II Thessalonians 2:15 is one of the clearest supports for Paul’s understanding of the sufficiency of the apostolic witness. Before it was written and contained in what we call the New Testament, the oral proclamation of the Word existed. Indeed, St. Paul did not know of a canon of 27 books and yet he knew fully of Scripture. At no time does Paul make one was superior to the other for they reflected the same Word and truth of Jesus Christ. If anything, it is far more significant that Paul includes letter here as a reference to his own self-understanding and the understanding of the Church that what was written (indeed what he wrote) was of equal weight and footing with the oral Word of the Apostles that came before it in time and yet stood together in truth as the one and the same Scripture: So, then, brothers, stand firm and hold to the traditions we passed on to you, whether by word of mouth or by letter.
The early Fathers of the Church understood it the very same way -- those who came as the written Word was first understood to be Scripture and those who knew only the written Word as Scripture. From a few of the early Fathers. . .
"The holy and inspired Scriptures are fully sufficient for the proclamation of the truth. St. Athanasius (Against the Heathen, I:3); "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." St. John Chrysostom (Homily 8 On Repentance and the Church, p. 118, vol. 96 TFOTC); "Let the inspired Scriptures then be our umpire, and the vote of truth will be given to those whose dogmas are found to agree with the Divine words." St. Gregory of Nyssa (On the Holy Trinity, NPNF, p. 327); "We are not entitled to such license, 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." St. Gregory of Nyssa (On the Soul and the Resurrection NPNF II, V:439); "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." St. Basil the Great (On the Holy Spirit, Chapter 7, par. 16)