Because of Paul’s mandate to “Preach the Word,” (II Tim 4:2), expository preaching is "theologically mandated by Scripture." So says David Allen, professor of preaching at Southwestern Baptist Theological Seminary in Fort Worth, Texas. Expository preaching "is preaching the text of Scripture, explaining it, illustrating it, and applying it...takes a text (a cohesive and structured expression of language that intends a specific effect) of Scripture, engages in exegesis to determine the meaning of that text of Scripture, constructs the fruit of that exegesis into a sermon (a discourse that explains the meaning of that text to people, illustrating and applying it as well)..."
I have found much on the World Wide Web written about sermons. A good bit of it claims that expository/exegetical/textual preaching is the kind of preaching most faithful to the Bible. This is usually supported by theological (such as Allen's above), logical and practical arguments (mostly these two). It is discouraging and disheartening that almost none of the discussions interact with the biblical "sermons" found in the New Testament. If they do, at least I have not found it.
On his heartcoreMethodist blog, Ted Campbell asks, “Is it possible that what the New Testament means by preaching is not quite the same phenomenon that goes by the name 'preaching' today?” This question is on the right track, but curiously, Campbell ran off the track pretty quickly. His thoughts centered on how brief were the "four verbatim sermons" by Peter and Paul. According to Campbell, he "timed the Greek text of Acts 2:14b-36, reading at a moderate pace." This experiment found the duration of Peter's sermon on Pentecost — "the longest recorded in the New Testament" — was "six minutes and fifteen seconds." He runs off the track when he chides those who think these texts only recorded summaries of these sermons with holding "the wickedest excuse for longer sermons." Campbell writes, "there’s nothing in the New Testament texts or in the ancient contexts to suggest that [these are not verbatim sermons but only summaries]." Surely Luke's statement (found in verse 40) that "with many other words did he [Peter] testify and exhort" at least suggest it! (And the timeline in Acts 3:1-4:3 suggests Peter's sermon and associated discussion in the temple area could have been up to three hours -- from the ninth hour until eventide, roughly 3 pm to 6 pm.)
The New Testament book of Acts records from possibly around 12 to 42 sermons – according to what you count as a sermon (e.g. is Acts 1:15-22 a sermon) and whether you count the mentions of sermons/preaching that do not record any of the content of the sermon. These must be engaged in any discussion of preaching and how sermons ought to function. It is perhaps that they do not fit well our preconceived ideas that we do not enter them into the testimony. (And this says nothing of the sermons of our supreme teacher and example, Jesus Christ.)
For those who demand expository sermons are "theologically mandated by Scripture" or are "most faithful to the Bible" we must ask the following questions.
1. What kinds of sermons are recorded in the New Testament? How many of them, if any, follow the pattern of the modern expository sermon?
2. Did Jesus preach topical sermons, textual sermons, none of the above, all or the above, or something else?
3. Is there any biblical record of Peter, Paul or any of the disciples preaching expository sermons (textually from a book or books of the Bible)?
4. Why does the command to "preach the word" mean expository sermons, especially if the one who laid down this mandate did not preach that way?
5. Is textual/expository preaching driven by a scriptural mandate, personal preference, education or something else?
But we should also consider:
6. To what extent do we follow the sermon examples of Jesus and the apostles, considering they spoke with a degree of inspiration and authority we do not have?
7. Were what we call sermons -- a single individual engaging in discourse or "lecture" to a crowd of people -- ever the basis of teaching and edification in the gathering of the church, or more for spreading the gospel of Jesus Christ to unevangelized peoples?
Lord willing, I hope to continue to engage this topic and these questions, first considering sermons of the book of Acts tomorrow.
[Note: such discussion is further impeded by the fact that phrases such as "expository preaching" and "topical preaching" do not always mean the same things to all people.]