In his book The Doctrine of the Knowledge of God, John Frame has an excellent discussion on the authority of Scripture. His point is simple and straightforward: the Bible is authoritative in everything it says.
This simple truth is profound, and we would do well to consider its implications. Frame refers to the great Princeton theologian Charles Hodge, who offered the following definition of theology:
Theology is the exhibition of the facts of scripture in their proper order and relation, with the principles or general truths involved in the facts themselves, and which pervade and harmonize the whole.2
Implicit in Hodge’s definition is the idea that the Bible, in its canonical form, is improperly ordered. Put this way, it is a rather shocking and even outrageous statement. That a Bible-believing Christian, especially one of Hodge’s stature, could suggest that the Scripture is imperfect in some sense is difficult to fathom. But there is no way to interpret his words in a more favorable way. For him, the task of theology is to take the improperly ordered raw materials of the Bible and place them in their proper order. And that naturally raises the question: what is the proper order?
For some, the “proper” order is the doctrinal propositions that can be extracted from the text. This view is evident in Richard Longenecker’s famous discussion of the exegetical method of the Apostles.3 He argues that the exegetical method of the Apostles is only to be followed when it yields the proper doctrine, which to his credit, is the “apostolic faith.” In other words, though Longenecker doesn’t explicitly say this, the authority of the Bible resides in the “apostolic faith and doctrine” that can be deduced from the Bible itself, but is not the Bible itself.
For confessionally minded Christians, the temptation is to locate the authority of Scripture in the confessions instead of the Bible itself. It is, for example, far easier to appeal to the propositional statements of the Westminster Confession of Faith and the Three Forms of Unity in adjudicating disputes than to invoke a poem or narrative. But to succumb to this temptation is to betray the confessions themselves, which affirm the Reformation notion of Sola Scriptura: the Bible itself is the highest and only infallible authority in the church.
More recently, some evangelicals have argued that the authority of Scripture is limited to what it reveals about the person and work of Jesus.4 On this view, one can say that “Paul was right theologically about Christ’s resurrection and salvation but wrong historically about Adam and the fall.”5 But such a view also undermines the authority of Scripture. If Paul affirms the historical Adam, on what basis can we reject his teaching? Or to put it more sharply, if the Bible affirms the historical Adam, on what basis can we reject it?
The Bible has authority because God is the primary author. Of course, I have no wish to diminish the involvement of the human authors. Each author wrote with a distinct style, vocabulary and perspective, but we must avoid the error that seeks to separate the divine word from the human: Let no one separate what God has joined together! The whole of Scripture is divine in origin; God is the author who stands behind all of the human authors.
Hence, John Frame is correct: the Bible is authoritative in all that it says. Its poetry is authoritative and must be interpreted as poetry. Its narratives are authoritative and must be interpreted as narrative. And so on and so forth. Moreover, we must avoid the erroneous view that suggests that the authority of Scripture resides in something outside of Scripture itself. Its authority does not lie in the doctrines that it yields, but in its very words themselves. Put differently, the deduced doctrines derive their authority from the Scriptures themselves and not the other way around. Or, to express this in Framean terms: doctrine is an application of Scripture, and as such, is distinct from Scripture.
Furthermore, the Bible’s authority does not reside in the theological truths that can be extricated from its historical statements. What the Bible affirms as historical must be embraced as historical truth. If God speaks through Paul (and he does), then we have no choice but to accept Adam as a historical figure. In Paul’s mind, Adam existed in history and his existence is presupposed in order to make a theological point. For Paul, the historical Jesus came to undo the problem caused by the historical Adam. Without a historical Adam, Paul’s theological argument in Romans 5 simply makes no sense.
In short, the Bible has authority in everything that it says for this reason and this reason alone: the Bible is the very Word of God.
 John M. Frame, The Doctrine of the Knowledge of God (Phillipsburg: P&R Publishing, 1987), 201.
2 Charles Hodge, Systematic Theology (Grand Rapids: Eerdmans Pub. Co., 1952), I, 19.
3 Biblical Exegesis in the Apostolic Period (Vancouver: Regent College, 1999), 198.
4 See, for example, the recent writings of Peter Enns. For an incisive analysis of Enns’ view of the authority of Scripture, see Hans Madueme, “Some Reflections on Enns and The Evolution of Adam: A Review Essay” in Themelios: Volume 37, No. 2, July 2012 (United Kingdom: The Gospel Coalition), 275-86.