We believe in biblical inerrancy. So what? How does the truth of biblical inerrancy and the authority of God's written revelation affect what we preach and how we minister? There's little point in defending the inerrancy of Scripture if we're unwilling to bow to the authority of Scripture in our approach to ministry.
This article is adapted from a paper written by John MacArthur at the height of the inerrancy debate in the early 1980s.
The theological highlight of 20th Century had to be evangelicalism's intense focus on the doctrine of biblical inerrancy.  Much of what was written defending inerrancy in the 1970s and '80s represented the most acute theological reasoning our generation has produced.
Yet it seems our practical commitment to inerrancy is somewhat lacking. The modern evangelical's commitment to the authority and inerrancy of the Bible doesn't always flesh out in ministry. Shouldn't our preaching reflect our conviction that God's Word is infallibly authoritative? Too often, it doesn't. In fact, there is a discernable trend in contemporary evangelicalism away from biblical preaching, and a corresponding drift toward experience-centered, pragmatic, topical messages in the pulpit.
How can this be? Shouldn't our preaching reflect our conviction that the Bible is the verbally inspired, inerrant Word of God? If we believe that "all Scripture is inspired by God" and inerrant, shouldn't we be equally committed to the truth that it is "profitable for teaching, for reproof, for correction, for training in righteousness; that the man of God may be adequate, equipped for every good work"?  Shouldn't that magnificent truth determine how we preach?
Clearly it should. Paul gave this mandate to Timothy: "I solemnly charge you in the presence of God and of Christ Jesus, who is to judge the living and the dead, and by His appearing and His kingdom: preach the word; be ready in season and out of season; reprove, rebuke, exhort, with great patience and instruction."  Any form of preaching that ignores the intended purpose and design of God is seriously deficient.
J. I. Packer has eloquently captured the pursuit of preaching:
Preaching appears in the Bible as a relaying of what God has said about Himself and His doings, and about men in relation to Him, plus a pressing of His commands, promises, warnings, and assurances, with a view to winning the hearer or hearers...to a positive response. 
The only logical response then to inerrant Scripture is to preach it expositionally. By expositionally, I mean preaching in such a way that the meaning of the biblical text is presented entirely and exactly as it was intended by God. Expository preaching is the proclamation of the truth of God as mediated through the preacher. 
Some who are known as expositors don't even believe in biblical inerrancy. It might also be the case that most who affirm biblical inerrancy don't practice expository preaching. (Again, the most popular trend among evangelicals these days is decidedly in the opposite direction--toward preaching driven by "felt needs," and other topical approaches to the pulpit ministry.) These are baffling inconsistencies, because an inerrantist perspective demands expository preaching, and a non-inerrantist perspective makes expository preaching unnecessary.
Putting it another way, what does it matter that we have an inerrant text if we do not deal with the basic phenomena of communication, e.g. words, sentences, grammar, morphology, syntax, etc. And if we don't, why bother preaching it?
In his landmark work on exegetical theology, Walter Kaiser pointedly analyzed the anemic state of the church due to the inadequate feeding of the flock:
It is no secret that Christ's Church is not at all in good health in many places of the world. She has been languishing because she has been fed, as the current line has it, "junk food"; all kinds of artificial preservatives and all sorts of unnatural substitutes have been served up to her. As a result, theological and Biblical malnutrition has afflicted the very generation that has taken such giant steps to make sure its physical health is not damaged by using foods or products that are carcinogenic or otherwise harmful to their physical bodies. Simultaneously a worldwide spiritual famine resulting from the absence of any genuine publication of the Word of God (Amos 8:11) continues to run wild and almost unabated in most quarters of the Church. 
The obvious cure for evangelicalism's spiritual malnourishment is expository preaching.
The mandate is clear. Expository preaching is the declarative genre in which inerrancy finds its logical expression and the church its life and power. Stated simply, inerrancy demands exposition as the only method of preaching that preserves the purity of Scripture and accomplishes the purpose for which God gave us His Word.
Or, as R. B. Kuiper succinctly stated it: "The principle that Christian preaching is proclamation of the Word must obviously be determinative of the content of the sermon." 
 The doctrine of biblical inerrancy is "the claim that when all facts are known, the Scriptures in their original autographs and properly interpreted will be shown to be without error in all that they affirm to the degree of precision intended, whether that affirmation relates to doctrine, history, science, geography, geology, etc." Paul D. Feinberg, "Infallibility and Inerrancy," Trinity Journal, VI:2 (Fall, 1977), 120.
 2 Tim 3:16-17
 2 Tim 4:1-2, emphasis added
 James I. Packer, "Preaching As Biblical Interpretation," Inerrancy And Common Sense, ed. Roger R. Nicole and J. Ramsey Michaels (Grand Rapids: Baker, 1980), p. 189.
 D. Martyn Lloyd-Jones, Preaching and Preachers (Grand Rapids: Zondervan Publishing House, 1971), p. 222.
 Walter C. Kaiser, Jr., Toward An Exegetical Theology (Grand Rapids: Baker Book House, 1981), pp. 7-8.
 R. B. Kuiper, "Scriptural Preaching," The Infallible Word, 3rd rev. ed., ed. Paul Woolley (Philadelphia: Presbyterian and Reformed, 1967), p. 217.