Of the four main attributes of Scripture—sufficiency, clarity/perspicuity, authority, and necessity—Kevin DeYoung has this to say in his new book, Taking God At His Word, in part interacting with Hebrews 1:1–4:
Of the four attributes of Scripture, this may be the one that evangelicals forget first. If authority is the liberal problem, clarity the postmodern problem, and necessity the problem for atheists and agnostics, then sufficiency is the attribute most quickly doubted by rank-and-file churchgoing Christians. We can say all the right things about the Bible, and even read it regularly, but when life gets difficult, or just a bit boring, we look for new words, new revelation, and new experiences to bring us closer to God. We feel rather ho-hum about the New Testament’s description of heaven, but we are mesmerized by the accounts of school-age children who claim to have gone there and back. From magazine articles about “My Conversation with God” (see chapter 2), to best-selling books where God is depicted as giving special, private communications, we can easily operate as if the Bible were not enough. If we could only have something more than the Scriptures, then we would be really close to Jesus and know his love for us.
Unless, of course, the finality of Christ’s redemption for us is intimately tied to the finality of his revelation to us.
Kevin DeYoung, Taking God At His Word: Why the Bible is Knowable, Necessary, and Enough, and What That Means for You and Me. (Wheaton, IL: Crossway Books, 2014), 43–44.