This idea of the singular authority of Scripture is the motivation behind much of the Protestant effort to translate the Bible into the native vernacular. In comparison, Eastern Orthodoxy has been motivated by its incarnational theology to translate not only the Bible but also the prayers and liturgies of the church. Conversely, the rejection of sola scriptura accounts for some of the resistance that the Catholic Church has historically shown towards translating the Bible and liturgies into local vernacular.
Sola scriptura reverses the order of the Church's authority, as it had been understood by the Catholic tradition. Instead of tradition being the interpretor of Scripture, sola scriptura makes Scripture the interpretor of tradition. It is the foundational claim of the Reformation.
Sola scriptura did not originally signify a radical rejection of all authority of the Church to interpret the Scriptures, but rather represented a claim that the teaching authority of the Church is regulated by the Bible, constrained by Scripture in both a limiting and a directing sense. The Reformers argued that the Scriptures are guaranteed to remain true to their divine source, and thus, only insofar as the Church retains scriptural faith it is assured of all the promises of God. Likewise, if it were possible for the Church to entirely lose Biblical faith, its authority would be reduced to nothing. Therefore, the Reformers targeted traditions which the Roman church had elevated to central issues of the Christian faith (such as transubstantiation, communion in one kind, that works of saints add to the church's treasury of merit, the doctrine of purgatory, the veneration of images, masses dedicated to the dead, and especially that the pope is the head of the Church), which the Reformers believed had no basis in Scripture, in the attempt to prove that the Church had gradually substituted traditions as the primary definition of the faith instead of the Bible, in order to demand of the Church that it should return single-mindedly to the Scriptures alone as the foundation of catholic faith.
Although it was not the Reformers' original intention to radically reject the teaching authority of the Church, there was not uniformity between the various Protestant movements. Because their early attempts to establish a consensus based on the Scriptures failed, the Reformation proceeded in three directions. The Lutheran exclusivists, the Reformed, and the Anabaptists had variously different ideas of the relation between Scripture and Tradition. The Anabaptist alternative history view, that the true Church became hidden or lost through a Great Apostasy dating from Constantine, radicalized their reforms and delegitimized their movement in the eyes of the other two branches so that they suffered persecution at the hands of both Catholics and Protestants. The Lutherans aimed at establishing an evangelical consensus immediately, but the Reformed brought diverse groups into international association with one another on more liberal principles, which damaged hopes of union with the Lutherans. The Reformation failed to coalesce into a single group, and from that time forward fragmentation based on sola scriptura has outpaced unions based on that principle.
The Church against which the Reformers directed these arguments did not see scripture and the traditions of the faith as mutually exclusive sources of authority; they believed that scripture was handed down through its traditions (accepted traditions were also perceived as cohesive in nature). The ones receiving the scripture trusted the people from whom they received it and their accompanying teachings. The proper interpretation of the Scriptures was seen as part of the faith of the Church. The meaning of Scripture was seen as proven from the faith universally held in the Catholic Christian churches, and the correctness of that universal faith was seen as proven from the Scriptures and apostolic tradition. The Biblical canon itself was thus viewed as part of the Church's tradition, as defined by its leadership and acknowledged by its laity.
The Catholic and Orthodox church leadership did not see any contradiction between the traditions that served as the source of scripture, and scripture as the source of this these traditions. The Scriptures of the Old and New Testaments were understood as oral traditions in writing, and other traditional writings produced within the Church through divine inspiration, and collected by the Church. In time, the Church's hierarchy through a series of councils identified the scriptures as authoritative and not subject to question in matters of doctrine. (See Biblical canon.) The various traditions that underlay Church doctrine were subsumed under a single doctrinal authority, of which the Scriptures were a part. Even if the authenticity or usefulness of some of the Scriptures was in doubt for a while, their authority was eventually recognized by agreement with the prevailing Catholic doctrine. In this prevailing view of early Christianity, the Scriptures are the principal Canon, the primary Tradition of the Church. Therefore, according to this view, to understand the Scriptures properly meant to convert to the Christian faith, to enter into that life and gain insight into that way of thinking and praying, in order to gain a catholic sense of what the Scriptures mean.
However, this view of scripture and tradition was not universally accepted within the Church. Throughout the history of the Church movements have arisen within the Catholic Church or alongside of it, which have not agreed with the official interpretation of the Scriptures. The leaders of these movements were often labeled heretics and their doctrines were excluded from the prevailing Church doctrine. According to Irenaeus, the Judaistic Ebionites less than one hundred years after the Apostles, charged that the Christians over-ruled the authority of Scripture by their traditions (Ebionites believed that keeping the Mosaic Law was an obligation for all men). Later, Arius (250-336), once he had been made a presbyter in Alexandria, began arguing that the catholic tradition concerning the deity of Christ was an invention of men, not found in the scriptures and not believed by the early Christians. Such teachings, however, were rejected as incompatible with both the Christian faith, and the Scriptures: which, as has been said, amount to the same thing in the understanding of those who defined the early Church doctrine. Since the New Testament had not been formally canonized yet, both the Ebionites and Arians were criticized and defeated based on the Jewish Scriptures (see Septuagint and Tanakh) and books that later became part of the New Testament, according to the interpretation found in the common teaching and worship of the Church hierarchy, and through other writings considered reliable. There are many other examples of the Church's reliance upon Scripture interpreted in a specific sense.
The Church held that the Bible is not meant to be given private interpretation, leaving each person to believe different things on matters of doctrinal importance. When disagreements arise, the correct interpretation of the Bible will be consistent with how the Church authorities have believed in the past, as revealed by the Ecumenical councils, the writings of the Apostles of Jesus and Fathers of the Church, and similar sources of Tradition (including, according to the Roman Catholics, the decisions of the Bishop of Rome). The truth, according to this view, was to be vindicated not only by appeal to antiquity, but by the presumed universality of the belief, and by the harmony also of prayers and liturgical elements with the catholic doctrines. This catholic view was described by St. Vincent of Lerins in the fifth century.
Nevertheless, the Protestant reformers believed, along with many other Roman Catholic scholars of their time and since, that the decisions of councils and pontiffs, and even the writings of the Church fathers, have a different authority than Scripture. It was their view, not uncommon in the Church, that the Scriptures are uniquely the rule of the Church. Therefore, many argued in their time, the study of the Scriptures is more important than the new science of Canon law. Many less radical reforms have been proposed in the Catholic Church based on these assumptions.
However, unlike their Catholic counterparts, the Protestants believed Catholic tradition as it had developed lately to be very seriously in conflict with the Scriptures: especially, with regard to teaching about the Church itself, but also touching on the most basic principles of the Gospel. They believed that no matter how venerable the traditional source, traditional authority is always open to question by comparison to what the Scriptures say. The Scriptures are alone to be relied upon, if the whole tradition were to speak against them. This, they said, had always been implicitly recognized in the Church, and remains a fail-safe against the corruption of the Church by human error and deceit. Corruptions had crept in, the Reformers said, which seriously undermined the legitimate authority of the Church, and tradition had been perverted by wicked men, so that by the traditions of men the authority of Scripture was being nullified.
So, sola scriptura represents a different view of history, than the traditional Catholic view: the Scriptures are the sole foundation of the Church's authority, the fountainhead of the Church's stream of traditions. 'Sola scriptura' was also a theological assumption: the Scriptures given by the Holy Spirit in the context of the Church, are a sufficient authority, self-authenticating and self-interpreting, communicating their meaning by the help of the same Holy Spirit in the context of the Church. The implications of these assumptions were elaborated in the doctrines developed by the Protestant Reformation, which were rejected by the Catholic Church.
Sola scriptura is still a doctrinal commitment of conservative branches of the Lutheran churches, Reformed churches, Baptist churches, and their offshoots, and other Protestants, especially where they describe themselves by the slogan, "Bible-believing" (See Fundamentalism). As with most slogans, the meaning of sola scriptura has been simplified over time. Instead of a theological revision of the idea of authority as understood by the Catholic Church, sola scriptura now commonly represents a presumed antithesis between every teaching of the Church vs. independent interpretations of the Bible by Protestants. For many Protestants, it has led to the belief that the Bible is the only source of Christian tradition; in some cases, these have abandoned many traditional Christian beliefs and practices because they don't find them supported or spelled out in the Bible, but not because they find them incompatible with or forbidden by the Bible.
The doctrine of sola scriptura has also made translating the Bible into local vernacular an important part of Protestant missionary work.
Some Christians, who doubt or reject both tradition and scripture as supreme over reason, may see liberty of conscience as the abiding legacy of the "sola scriptura" rhetoric of the Reformers. There is no question that the rhetoric of the Reformation and especially sola scriptura, has excited profound doubts concerning the Church's authority, which has resulted in disunity and innovation far beyond the intentions of the original reformers.
See also:
The singular authority of Scripture
Scripture and Tradition
Tradition vs. Scripture
Legacy