I am not addressing the canon of scripture, or the process by which the biblical texts were included as the authoritative written basis of christianity. That is another topic. This article is about the USE & AUTHORITY of the scriptures already canonized into what we now call the Bible. The early bishops, writers, historians, & apologists in the church attested to the importance of these scriptures. They were reaffirmed during the reformation, & many times before & since. The authority of the canon of scripture is a constant thread in the history of the christian church. The ONLY record of the words & teachings of Jesus are from the historical gospels, & the men who wrote & compiled the accounts. No apocryphal writings or later 'commentaries' or revisions have any basis, but are superfluous at best, & deceptions at worst.
Sola Scriptura has several key parts:
1. Inspiration. It is a revelation from God to man. That is the basis for its authority.
2. Sufficiency & Final Authority. The teachings from scripture override any mandates or decrees of men or councils, & is sufficient for faith. No additions or subtractions from the clear teachings of scripture are needed or desired.
3. Clarity (or perspicuity) & scripture interpreting scripture. "...those things which are necessary to be known, believed, and observed, for salvation, are so clearly propounded and opened in some place of Scripture or other, that not only the learned, but the unlearned, in a due use of the ordinary means, may attain unto a sufficient understanding of them." ~ Westminster Confession of Faith, 1646. This concept is one of textual hermeneutics, a process of determining the intent of the writer. No special gifts or dispensation is required, but only typical reason & understanding of human communication. "The infallible rule of interpretation of Scripture is the Scripture itself: and therefore, when there is a question about the true and full sense of any Scripture (which is not manifold, but one), it must be searched and known by other places that speak more clearly." ~ Westminster Confession of Faith, 1646
Here are some quotes from early church fathers.
"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." ~ Irenaeus, “Against Heresies” 3.1.1, c. AD 180
"Have thou ever in your mind this seal , which for the present has been lightly touched in my discourse, by way of summary, but shall be stated, should the Lord permit, to the best of my power with the proof from the Scriptures. 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 thou 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." ~"The Catechetical Lectures of S. Cyril" Lecture 4.17, c. AD 347
This is a very good summary of the early church fathers, their esteem of the scriptures, & their place in early church history.
"Centuries of experience have tested the BIBLE. It has passed through critical fires no other volume has suffered, and its spiritual truth has endured the flames and come out without so much as the smell of burning" ~W.E. Sangster