Professional standup comedians can hold a person's attention all by themselves while they walk a bare stage. They're really good at that. Most preachers aren't. But the solo standup performance which may run an hour or more is made up of many connected bits, each of which has been honed to perfection. Each of these bits is the essence of the standup art. In a comedy club or bar, the standup comedian is on for a much briefer time, along with other acts. On TV, when making a guest appearance, it's even tighter. How tight? Six minutes. The gold standard in standup comedy is the ability to hold the audience's attention for six minutes. That's a whole evening's performance, right there. Only the best get to work solo, making up a longer performance out of many six-minute routines.
Sermonizing allows for a bit more latitude, but not that much. The best sermons are probably in the fifteen minute range. When you go beyond twenty minutes, you begin losing your congregation. When you stretch to thirty or forty minutes, let's face it: there's an awful lot of padding in there. Now, I'm a professional. I have a fairly long attention span. But when it becomes clear that your outline is not progressing, that you're repeating points you made earlier, and you still can't bring it to a close, then it's obvious that you either put in too much (because you didn't have the discipline to choose which elements would be most effective), or you're floundering around trying to reach the perfect (emotionally satisfying) ending.
At the dedication of the Gettysburg National Cemetery, Edward Everett spoke for two hours. President Lincoln spoke for two minutes. Nobody remembers what Everett said, but we still ponder Lincoln's words. It's now how much you said. It's what they remember out of all the stuff you laid on them. Sermons, like many other things, are subject to the law of diminishing returns. And all the rest of the service is not merely the "preliminaries" to the main event (listening to you talk).
When I was working on my doctorate, I taught the beginning class in Teacher Education several times. It was a one-hour class whose main requirement was twenty hours of field observation in the classroom. I only gave a few class lectures, and only at the barest, most introductory level. But one thing I always taught these college sophomores was this: The size of your truck determines how many vegetables you can take to market, at least in one trip. In other words, you have to adapt what you do to the time available. If you have a 45-minute class period, you can't do your normal 55-minute lesson plan. It won't fit. And even in a 55-minute period (not to mention, a longer, 75- or 90-minute "block"), the attention spans of the students won't often let you do just one thing for the whole period. You lecture a few minutes, then you do group work or exercises or something. Sometimes, you do three different things in a class period.
A service of worship is not necessarily 60 minutes, but that is the usual expectation. I've attended churches where it was deliberately set at 70 or 75 minutes. That's fine. And if you occasionally go over because there were professions of faith or special music or a spontaneous surge toward the altar, great. Nobody minds those extensions. But usually, there is an expectation of how long the service should be. The pastor is the one responsible for time management within that period of time. He or she should know what can be accomplished and what can't. And if the pastor is also the preacher, then he or she should adjust the sermon time so as to fit in all the elements of worship so that everything gets "done decently and in order." And remember, the apostle also said, "the spirits of the prophets are under the control of the prophets." If you just can't get it all in without doing violence to the other parts of the service or without slopping over all the time, then you are out of control.
I remember one Easter Sunday years ago. The church was packed. The choir was ready for the big day with the big music. We had seven persons to baptize and/or confirm. And we were celebrating communion. One mom said, "Oh no, we'll be here forever." I said, "watch me." Now, I usually preached the shortest sermon of the year in the main service on Easter Sunday, anyway. The regulars were all tired by the end of the big weekend, and the visitors were restless and didn't know how to pay attention that long, so I tightened up the sermon in order to maximize what they could retain. Then, I had added more communion servers so that people coming forward and returning to their seats would go more quickly without anyone feeling rushed. We did it all, without rush or confusion. Every individual bit was great. And after I gave the benediction, as the liturgist and I processed down the aisle toward the sanctuary doors, I turned to him and asked the time. The whole service was fifty-eight minutes.
That was my first Easter in that church. I stayed eight years in all, and I never got complaints about running over. Because if and when we did run over the expected time, it was plain that the Spirit himself was leading that way, not because I was lost, or trying to do too much, or searching for the perfect way to finish. Managing your time effectively is not quenching the Spirit. It's controlling oneself in submission to the Spirit.