In the old phenomenon of the New Homiletic the sermon was not so much about what you say, it was about what you do with your words as a preacher. The insight that words not only serve to say things but that they also do things, that they are intended to address circumstances, it seems to me, is overstated when the doing eclipses the saying, as is apparently the case with the New Homiletic. But the insight itself if good, and a useful consideration for the preacher.
I have been instructed in three frames of reference for preaching: rhetoric, poetics and theology. I think the theological frame of reference is the one that needs least attention from me. Rhetoric, for all that it is a familiar word, is perhaps not so clear. To what, after all, does it apply? I think rhetoric is the way of measuring what is appropriate to your setting. Public speech is not like a private conversation, and the speaker will do best when most conscious of this.
We will not think rightly of rhetoric if we think it is something trivial such as superfluous adornments, or artificially restricted or enhanced diction. It is not—sorry Plato—a knack for making something seem desirable regardless of what it actually is (though Socrates can hardly be blamed for thinking this way). One of the funny things about public speaking is that it is not your natural speech, but it works best when it comes across as natural. Rhetoric is how you measure what artifice corresponds to your artificial setting in order to offset it. Your setting is contrived, but you must not seem contrived in your speech: plan for that. And so I think I can say that rhetoric is about eliminating distractions.
Poetics, on the other hand, is about creating interest. In this the New Homiletic is on to something, insofar as I understand it. There is a dramatic structure to a sermon, a beginning middle and end to it, a correct and fitting way to make people interested in what you’re doing and where you’re going. It is something your words are intended to accomplish, a place of emotional emphasis to which it builds and from which it winds down, that kind of thing. Too many preachers, blissfully unaware of the New Homiletic, conceive of the sermon as an information dump. That is a sovereign recipe for effectively boring God’s people with God’s word. If you think of a sermon as an information dump, something boring is not what you will intend to say, but that is what you will do. That is not to say that content doesn’t matter, but content can’t be your only concern.
Another thing I find interesting (having been disabused by dissidens some years ago when he pointed me to Edmund Clowney) is to see how many preachers also think an outline is a device for guiding their hearers through the sermon, employed so that they know where they are and so that they do not wander. I was once told to think of outlines as skeletons: something nobody wanted to see. I think that is a good insight. The point of the outline, rather than guiding the listener, is to give your sermons structure and coherence. This, of course, is essential to being interesting, but it is just an element, and probably the least apparent. I think it is probably an element of rhetoric, but since the sermon is one whole, rhetoric and poetics are going to interpenetrate. The poetic and more apparent element to your hearer is that you are obviously doing something: are raising a question, following an investigation, drawing them into the story in the text, etc. They follow you because you know how to create interest in what you want to get across just by the way you approach it.
Augustine had good words on being interesting, from what we may call the Old Homiletic. “If it is done in a disagreeable way, the benefits reach only a few enthusiasts, who are eager to know the things they need to learn no matter how dull and unattractive the teaching may be.” Which reminds me of churches where you get an information dump guided by an extensive, tedious outline. It benefits the few enthusiasts, that is all. That is not all, however, Augustine enjoins. “Learning has a lot in common with eating: to cater to the dislikes of the majority even the nutrients essential to life must be made appetizing.” De Doctrina Christiana 4.72-3