How long should a sermon be? There’s no universal answer to that question – unless you opt for the Holy Spirit gambit and claim you or your pastor preach inerrantly as the Spirit dictates.

The truth is, I can tell a lot about a person’s religious background or current preferences by their honest answer. That’s one of the first lessons a military chaplain learns. Different traditions possess vastly different expectations about sermon lengths.

There are plenty of individual exceptions to the rule, of course. But let me throw out a couple generalizations. People in mainline churches think the sweet spot is around 15 minutes. For many, 12 would be even more desirable, although most can tolerate 20 minutes before beginning incessant time checks on their watches or other devices. In the minds of some, brevity is next to godliness.

For many evangelicals, particularly pentecostals and more fundamentalist communions, a 15 minute sermon is an oxymoron. Anything less than half an hour is simply a devotion or meditation, and any preacher worthy of the title should be able to preach a 45 minute sermon without working up a sweat.

So, in the case of a chaplain preaching for two to three different congregations on a Sunday morning, you would need to tailor your sermons differently for various congregations. Otherwise, if you attempted to strike a happy medium, you ran the risk of having your evangelicals feeling shortchanged and your mainline protestants with eyes glazing over.

Recognizing these differences is helpful, lest we slip into that normal misconception that our assumptions/experiences/logic are shared by others. One evangelical seminary professor, clearly writing for others from a similar tradition as his own, illustrates my point.

The average sermon length, according to one poll, ranges 20 to 28 minutes. If this statistic is accurate, it is a telling indicator of the spiritual depth of today’s churches. Many churches have already discontinued their evening services. With the trend of reducing the length of Sunday morning sermons, our generation is receiving less than half the biblical teaching our parents sat under.

The better a person understands the Word of God, the more they will grow spiritually. . . . I find it difficult to believe that current pastors and their 20 minute sermon-ettes can reach any level of comparable depth to the 80 minutes (or more) pastors used to be given (between the morning and evening services).

I have been pondering this subject not because my own pastor’s sermons are too long. Actually, a few days ago the delightful newsnote, “Today in Christian History,” featured an intriguing note. It is one of Christianity Today’s free newsletters.

It described an incipient Crusade that was derailed before it set out, due to too much of a good thing (too much preaching).

September 26, 1460: Pope Pius II assembles European leaders, then delivers a three-hour sermon to inspire them to launch a new crusade against the Turks. The speech works, but then another speaker, Cardinal Bessarion, adds a three-hour sermon of his own. After six hours of preaching, the European princes lose all interest in the cause; they never mount the called-for crusade.

This is precisely the sort of event I cannot resist learning more about. In short, Pius was a talented orator who had written popular erotic literature during his pre-papal years. Bessarion was a Greek priest who coordinated the effort of Byzantine Emperor John VIII Palaeologus to reunite the Eastern and Western churches to protect Constantinople from the Turks. In 1463, a decade after the city fell to the Ottomans, Bessarion was appointed the Latin Patriarch of Constantinople.

If only Cardinal Bessarion had preached a shorter sermon, perhaps the glorious Hagia Sophia would still resound with the praise of Christ.

How to Measure Sermons

One of the worst ways to weigh a sermon, to consider its worth, is by considering its duration. There is nothing intrinsically better about a sermon that lasts 20 minutes than one of half that length. Barring extremes (e.g. Pius’ and Bassarion’s extended monologues or some jargon-laced, religious pop message modeled after fleeting modern commercials), duration matters little.

I think we could all agree that it is the substance of the message which is shared, that matters. This is where the Holy Spirit leads the way. The sermon should be based on God’s truths. It should be tailored to meet the needs of its particular hearers. And it should be timely, attuned to this specific moment.

Unfortunately, we do tend to associate sermons with extended lectures. In a 1962 letter to one of his regular correspondents, Lewis responds to her question about animals and heaven. After explaining his view, he concludes the letter with an apologetic “But this is turning into a sermon!” In truth, his comments are of the ideal duration to address the question at hand.

And that – an ideal length for the specific context – is the goal for which all preachers should strive.

A Mere Inkling Bonus

I’ve written about the importance of listening to sermons in the past. It includes an entertaining account of C.S. Lewis’ boredom during some of the sermons in his home parish. You can also read here about Lewis’ own experiences as a preacher.

One of C.S. Lewis’ rewarding essays is entitled “The Sermon and the Lunch.” Lewis uses the occasion of a sermon to explore the nature of family. The pastor offers a textbook endorsement of the importance of family, where “we can fling aside the weary disguises of the outer world and be ourselves.” Thereupon, he quickly loses the congregation’s attention.

Lewis’ own thoughts are distracted by his awareness of the pastor’s own family. Having been a guest in the home, Lewis knows the family dynamics fall far short of the ideal he is presenting. However, it is not hypocrisy which disturbs him. It is the fallacious premise upon which the sermon is based. You can read the entire essay at the link on its title in the previous paragraph, or you can listen to a reading of the essay on the link below. Here, however, is the reason for Lewis’ discomfort.

The memory of that lunch worries me during the last few minutes of the sermon. I am not worried by the fact that the Vicar’s practice differs from his precept. That is, no doubt, regrettable, but it is nothing to the purpose. As Dr. Johnson said, precept may be very sincere (and, let us add, very profitable) where practice is very imperfect, and no one but a fool would discount a doctor’s warnings about alcoholic poisoning because the doctor himself drank too much.

What worries me is the fact that the Vicar is not telling us at all that home life is difficult and has, like every form of life, its own proper temptations and corruptions. He keeps on talking as if ‘home’ were a panacea, a magical charm which of itself was bound to produce happiness and virtue. The trouble is not that he is insincere but that he is a fool. He is not talking from his own experience of family life at all: he is automatically reproducing a sentimental tradition – and it happens to be a false tradition. That is why the congregation have stopped listening to him.