Joel Beeke on the limits of the sufficiency of Scripture:
The sufficiency of Scripture is, however, limited to the Bible’s purpose in revealing truth for our salvation, faith, and obedience (Ps. 19:7–11; John 20:31). The doctrine does not assert that the Bible is sufficient to guide all human activities in every respect, except in the most general way. The Bible does not claim to be a comprehensive encyclopedia of everything. Instead, it gives us “the words of the wise” so “that thy trust may be in the Lord” (Prov. 22:17, 19). The Holy Scriptures “are able to make thee wise unto salvation through faith which is in Christ Jesus” (2 Tim. 3:15). It is “profitable for doctrine, for reproof, for correction, for instruction in righteousness” (v. 16). Other matters must be governed by “the general rules of the Word, which are always to be observed,” such as “Whatsoever ye do, do all to the glory of God” (1 Cor. 10:31).
Calvin on Isaiah 8:20:
Hence we learn that everything which is added to the word must be condemned and rejected. It is the will of the Lord that we shall depend wholly on his word, and that our knowledge shall be confined within its limits; and therefore, if we lend our ears to others, we take a liberty which he has forbidden, and offer to him a gross insult. Everything that is introduced by men on their own authority will be nothing else than a corruption of the word; and consequently, if we wish to obey God, we must reject all other instructors. He likewise warns us that, if we abide by the law of the Lord, we shall be protected against superstitions and wicked modes of worship; for, as Paul calls the word of God “the sword of the Spirit, ” (Ephesians 6:17), so by the word, Satan and all his contrivances are put to flight. We ought therefore to flee to him whenever we shall be attacked by enemies, that, being armed with it, we may contend valiantly, and at length put them to flight.
Source: https://www.puritanboard.com/threads/sola-scriptura.91225/, Comment 1
“This principle does not mean what it has often been made to say by American evangelicals, i.e., “No creed but Christ,” or “We read Scripture as if no one else has ever read it before,” or “I and my Bible are the sole authority.”…
Sola Scriptura asserts that the Scriptures are the final, unique, and therefore sole magisterial authority for the Christian faith and the Christian life. It asserts the sufficiency of Holy Scripture for the Christian faith, Christian worship, and the Christian life. It does not make the Scriptures into a manual for mechanics and bakers but recognizes that Scripture is enough for what it intends to do, that its authority is final where it speaks.”
Read more: https://heidelblog.net/2017/03/sola-scriptura-protects-christian-liberty/
Reformation SA.org on the political and social fruits of the Protestant Reformations:
“Sola Scriptura eroded the foundations of ecclesiastical and political totalitarianism. Instead of the prevailing “Rex Lex” (the king is the law), the Reformers championed “Lex Rex” – the Law is king! No one is above God’s Law… The Protestant emphasis on the Priesthood of all Believers led to the concept of representative republics and democratic forms of government. It fostered freedom of religion and freedom of conscience which led to freedom of speech, freedom of the press, freedom of association and all the other out-workings of political and social freedom.”
Read more: http://www.reformationsa.org/index.php/reformation-today/110-reformation-or-desecration
“So much study and reflection on the subject is bound up with [Scripture] that no person can possibly do it alone. That takes centuries. To that end the church has been appointed and given the promise of the Spirit’s guidance into all truth. Whoever isolates himself from the church, i.e. from Christianity as a whole, from the history of dogma in its entirety, loses the truth of the Christian faith. That person becomes a branch torn from the tree and shrivels, an organ that is separated from the body and doomed to die.”
Source: http://www.puritanboard.com/showthread.php/89164-My-debate-with-a-Oneness-Pentecostal-pastor-on-March-Need-help-with-quotes!, Comment #7
The historic Reformed view of Sola Scriptura:
Westminster Confession of Faith 1.6: The whole counsel of God concerning all things necessary for his own glory, man’s salvation, faith and life, is either expressly set down in Scripture, or by good and necessary consequence may be deduced from Scripture: unto which nothing at any time is to be added, whether by new revelations of the Spirit, or traditions of men. Nevertheless, we acknowledge the inward illumination of the Spirit of God to be necessary for the saving understanding of such things as are revealed in the Word: and that there are some circumstances concerning the worship of God, and government of the church, common to human actions and societies, which are to be ordered by the light of nature, and Christian prudence, according to the general rules of the Word, which are always to be observed.
R. Scott Clark on the switch from Sola Scriptura to Biblicism:
“Under the influence of Anabaptist radicalism, which swept across and transformed American evangelicalism in the 19th century (the causes of which are the subject of another post) led it away from the Reformation understanding of sola Scriptura to a different doctrine: biblicism or the attempt to understand Scripture by one’s self and by itself, i.e., in isolation from the history of the church and in isolation from the communion of the saints. In biblicism the interpreter, not Scripture, becomes sovereign. Historically biblicists, although they boast about their devotion to Scripture, are actually devoted to the supremacy of reason. As someone, somewhere said, “All heretics quote Scripture.” It is one thing to quote Scripture but it is another to read it well and to interpret it properly.”
Read more: http://heidelblog.net/2015/04/the-difference-between-sola-scriptura-and-biblicism/
Christianity in its living principles and its outward forms is purely a matter of Divine revelation. The great error of the Church in all ages, the fruitful source of her apostacy and crime, has been a presumptuous reliance upon her own understanding. Her own inventions have seduced her from loyalty to God, and filled her sanctuary with idols and the hearts of her children with vain imaginations. The Bible cuts at the very root of this evil by affording us a perfect and infallible rule of faith and practice. The absolute perfection of the Scriptures as a directory to man was a cardinal principle of the Reformation, and whatever could not be traced to them either directly or by necessary inference was denounced as a human invention – as mere will-worship, which God abhors so deeply that an inspired Apostle has connected it with idolatry or the worshiping of angels.
~ James Henley Thornwell, The Regulative Principle Applied to Church Government