Every age, as C. S. Lewis once observed, is especially prone to make specific mistakes; and so we need to try to identify the characteristic errors of our age so that we can strive to avoid them. One of the worst errors among Christians in our time is a tendency to reject systematic theology.
As Michael Horton observes, systematic theology is now regularly rejected by liberals and conservatives alike. Liberals reject it because they don't believe that the Bible is God's one, inerrant Word. They see the Scriptures as a collection of conflicting and erring human words that can't be systematized. Conservatives are also inclined to reject it, but for precisely the opposite reason. Because they are convinced that the Scriptures are God's one, inerrant Word, they are wary of any system of potentially erring human theology being imposed on the inerrant Scriptures.
Conservatives often have other reasons to neglect or spurn systematic theology. Reading a book of systematic theology, no matter how often it cites Scripture, can still seem to be keeping us one step away from God's actual Word. So we turn to the Scriptures themselves, often first by reading a "devotional" that opens with one little scrap of Scripture each day. As we mature, we may begin reading through whole biblical books. Sometimes this leads to our studying a whole book inductively, where we try to identify each of its parts and then understand how each part furthers the purpose of the whole book. For instance, I may try to determine how each section of Luke's Gospel contributes to his goal of writing "an orderly account" of "the things that have been accomplished among us," so that his readers "may have certainty concerning the things [they] have been taught" (see Luke 1:1-4).
Reading whole biblical books inductively makes sense, since God brought his Scriptures into being through inspiring a number of human authors, yet without overriding their normal thinking processes. Consequently, understanding how a biblical writer is thinking is important for understanding what God is communicating to us through that author's words. For instance, in his first epistle John repeatedly tells his readers why he is writing to them-so that they may not sin (1 John 2:1), so that they may know that they have eternal life (5:13), and so on. Knowing his specific goals in writing helps us to put the rest of what John writes in its proper context. Moreover, we need to pay attention to the differing genres and styles of the various biblical books, even though, as I argue in my other sidebar, "Why Must Christian Theology Conform to Scripture?," every word of these diverse writings is really a word from God.
Because Scripture has this unique kind of dual authorship, much of the way that we get closer to understanding God's word to us in Scripture involves our paying closer attention to the words and intents of its human authors. Consequently, a lot of Christian reading should involve careful study of whole biblical books. And a lot of Christian preaching should be expository in the sense of involving careful, week-in-and-week-out preaching through whole books. But there is also a risk here, for we can get so caught up in seeing the various books of Scripture as separate and diverse and distinctive human productions that we lose sight of their being part of God's one, inerrant Word. For instance, I may get so caught up in thinking about what John says about our Lord that I forget to interpret it in the light of what Paul says about him.
There is also a temptation here. We can be tempted to think that we have honored the Bible as God's one, inerrant Word when we are in fact treating it as if it is nothing more than a lot of separate human words. In fact, I think succumbing to this temptation is part of the reason why systematic theology has fallen out of grace with biblical conservatives. When bright young conservatives pursue advanced degrees, they often go to universities where their teachers do not believe that the Bible is God's one, inerrant Word. Yet these professors may find various pieces of Scripture to be interesting and worthwhile, either as a collection of human words or as something divinely inspired and yet less than wholly and inerrantly God's Word. So the easiest way for these conservatives to get through their graduate programs is for them to emphasize just the human dimension of Scripture's dual authorship. They don't outright deny that the Bible is God's one, inerrant Word, but they get out of the habit of treating it as such. They no longer have, at the forefront of their consciousness, what Christians have always affirmed-that God is the primary author of Scripture.
But if God is Scripture's primary author, then we must read the Bible as one book. This requires us to read it, as Richard Lints says, as one whole story-one whole drama-with a beginning and a middle and an end. We must read Scripture as biblical theologians do, focusing on its total redemptive/historical character. But we cannot stop even there. When Paul lists the qualifications for church elders, he states that an elder must "be able to give instruction in sound doctrine and also to rebuke those who contradict it" (Titus 1:9). Elsewhere in Scripture it is clear that every Christian is supposed to grow toward doctrinal maturity, so that we can know and proclaim and defend our faith (see, e.g., Acts 2:42; Eph. 1:17-20; Col. 1:28; Heb. 5:11-6:1; 1 Pet. 3:15, 16). This requires systematic study of the Scriptures, study that goes through the whole Bible seeking answers to particular doctrinal questions, such as," Does God know everything about the future?" or "How are we to think about Jesus as both human and divine?" As Michael Horton writes, "A month of inductive Bible studies is unlikely to lead a person to the doctrine of the hypostatic union of the two natures of Christ." This is where we need to read books of systematic theology that are saturated with Scripture, for rather than keeping us one step removed from God's actual Word, they actually help us to understand it as one consistent set of truths.
D. A. Carson has said that biblical theology is a "mediating discipline" while systematic theology is a "culminating discipline." Even biblical theology, in spite of its emphasis on the Bible as one story, goes only part of the way to what God intends us to get from Scripture, which includes our getting a systematic understanding of who he is and what he has done for us in Christ. Just as there is a culmination to a great symphony, where all of its themes come together and are properly wrapped up, so there should be a culmination to all of the biblical reading that we do, a culmination that includes our coming to understand what the whole Bible has to say about all of the crucial questions of life. We need to understand not only what the Apostle Paul has to say about who God is, but also what Moses has to say and what the psalmist has to say and so on through all of the biblical authors. We need to reach the kinds of conclusions that I reach in my other sidebar on what Scripture says and assumes about itself. We need to reach the kinds of conclusions about the Trinity, the Incarnation, and divine sovereignty and human freedom that Michael Horton highlights in his piece.
God made our minds so that they rest when they come to understand, in a systematic way, a whole range of truth. Of course, we may want our minds to rest too soon and thus we may neglect to check our theological conclusions against Scripture as carefully as we should. And of course God means for the Bible to be more to us than just a sourcebook of truths; he means for its varied genres-for instance, its history, its poetry, and its wisdom literature-also to affect us in various ways. Yet if we want to honor the Bible as God's one, completely true Word, then we must seek to understand everything that it tells us on every important biblical topic. We will also want to organize these biblical truths systematically so that we can see, for instance, how God's nature governs what he does for us in Christ. Anything less than this kind of systematic study-and the sort of systematic preaching through the great heads of doctrine that should arise from it-doesn't complete the task of honoring Scripture as God's one, inerrant Word.