Sola scriptura (Latin ablative, "by scripture alone") is the doctrine that the Bible contains all knowledge necessary for salvation and holiness. Consequently, sola scriptura demands only those doctrines are to be admitted or confessed that are found directly within or indirectly by using valid logical deduction or valid deductive reasoning from scripture. However, sola scriptura is not a denial of other authorities governing Christian life and devotion. Rather, it simply demands that all other authorities are subordinate to, and are to be corrected by, the written word of God. Sola scriptura was a foundational doctrinal principle of the Protestant Reformation held by the Reformers and is a formal principle of Protestantism today (see Five solas).
During the Reformation, authentication of scripture was governed by the discernible excellence of the text as well as the personal witness of the Holy Spirit to the heart of each man. Furthermore, per sola scriptura, the relationship of Scriptural authority to pastoral care was well exampled by the Westminster Confession of Faith which stated:
VII. All things in Scripture are not alike plain in themselves, nor alike clear unto all; yet 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.