Here are some quotes on the clarity of Scripture. I particularly enjoyed Herman Bavinck’s.
“You see, then, that the entire content of the Scriptures has now been brought to light [with Christ’s coming], even though some passages which contain unknown words remain obscure,. Thus it is unintelligent, and ungodly too, to pronounce them obscure on account of those few obscure words. If words are obscure in one place, they are clear in another. What God has so plainly declared to the world is in some parts of Scripture stated in plain words, while in other parts it still lies hidden under obscure words. But when something stands in broad daylight also, it does not matter whether there is any evidence in the dark.” (Martin Luther, Bondage of the Will, p. 71-72) One of Luther’s key arguments against Erasmus in the book is that the Scriptures are clear.
“All things in scripture are not alike plain in themselves, nor alike clear to all; yet those things which are necessary to be know, 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 ordinary means, may attain unto sufficient understanding of them.” (Westminster Confession of Faith, Chapter I, Article VII)
“Are the Scriptures so perspicuous [clear] in things necessary to salvation that they can be understood by believers without the external help of oral tradition or ecclesiastical authority? We affirm against the papists.” (Francis Turrentin, Institutes of Elenctic Theology, II:17)
“The doctrine of the perspicuity [clarity] of Holy Scripture has frequently been misunderstood and misrepresented, both by Protestants and Catholics. It does not mean that the matters and subjects with which Scripture deals are not mysteries which far exceed the human intellect. Nor does it assert that Scripture is clear in all its parts, so that no scientific exegesis is needed, or that, also in its doctrine of salvation, Scripture is plain and clear to every person without distinction. It means only that the truth, the knowledge of which is necessary to everyone for salvation, though not spelled out with equal clarity on every page of Scripture, is nevertheless presented throughout all of Scripture in such a simple and intelligible form that a person concerned about the salvation of his or her soul can easily, by personal reading and study, learn to know the truth from Scripture without the assistance and guidance of the church and the priest.” (Herman Bavinck, Reformed Dogmatics, Vol. 1, p. 477)
“God is fully in control of his communications to human beings. When he intends to communicate with a human being, he is always able to do it successfully. But another name for successful communication is clarity. An unclear word is one that does not succeed, that fails to accomplish its purpose. But we know that God’s Word always accomplishes its purpose (Isaiah 55:10-11). Therefore his word is always clear.” (John Frame, The Doctrine of the Word of God, p. 204) Frame is in agreement with the statement above by the Westminster Confession of Faith. His quote needs to be read in that light.
“We are right to trust that God in Scripture has spoken and continues to speak sufficiently clear for us to base our saving knowledge of him and of ourselves, and our beliefs and our actions, on the content of Scriptures alone, without ultimately validating our understanding of these things or our confidence in them by appeal to any individual or institution.” (Timothy Ward, Words of Life, p. 127)
“The doctrine of the clarity of Scripture is not a wild assertion that the meaning of every verse in the Bible will be patently obvious to everyone. Rather, the perspicuity of Scripture upholds the notion that ordinary people using ordinary means can accurately understand enough of what must be known, believed, and observed for them to be faithful Christians.” (Kevin DeYoung, Taking God at His Word, p. 59)