It is a perennial question pondered by the preacher — how long should my sermon be? 

Recently a friend took an informal poll on Twitter, asking, "How long do you normally preach?" The answers varied, as one might expect, and some discussion ensued as to what the "best length" for a sermon might be. Is there such a thing?

I'll offer my opinion on that at the end of this post, but in general, I agree with the dictum that the best sermons can't be too long and the worst sermons can't be too short. But all things being equal, I do think there's such a thing as a sermon that's too long and a sermon that's too short. Here I suggest five reasons for each error. Firstly:

Your sermons shouldn’t be too short, because . . .

1. Sunday is often the only Bible your people get each week.

It's sad, but it's true. It shouldn't be the case, but it often is. The most Bible many (most?) of your people will get each week will be in the Sunday morning worship time. All the more reason not to short-shrift your sermon time. Your people need deep Bible. 

2. The word of God is worthy of sustained attention, not drive-by sampling.

Too-short sermons treat the Scriptures like a shallow reservoir for tasting, not a deep well for eternal sustenance. Don't treat the Bible in your services like a Bartlett's Book of Quotations or a spiritual buffet for personal improvement, and don't treat the sermon like a half-time speech or a motivational TED talk. The word of God is worthy of our attention, of all our efforts to dwell in it. Short-shrifting the sermon communicates to people that the Bible—and thus God's glory—is not worth gazing at. Train your flock through your preaching to behold.

3. Hearing from God should have the most prominent place in the gathering.

Sometimes we short-shrift the sermon out of service time constraints, but then it is easy to get priorities out of whack. Consider this: it is more important for us to hear from God than it is for God to hear from us. Both are necessary, of course! But if your creative elements outweigh the preaching in a service, things are out of whack. Even our worship in singing, which is vitally important for congregational encouragement and a reflection of God's worth, is not as important as hearing from God's word. God deserves our words, but he can live without them. We, on the other hand, cannot live without a word from God. Teach your people to weigh hearing from God as more glorious than our self-expression.

4. The church should subvert — not support — convenience culture.

Sometimes preachers of short sermons defend the act by noting the short attention spans common to our culture. But the church isn't called to reflect the culture back to itself, but to train followers of Jesus to live in counter-culture ways. So consider this: you don’t want your church service to aid the culture in eroding people’s shortening attention spans. In an age of short-attention spans and soundbite philosophy, we ought to work toward our people's endurance, patience, and all the other kingdom-worthy values that substantive preaching supports.

5. Sermons that are too short don’t often do justice to biblical texts.

The word of God is rich and ought to dwell richly in us. It is difficult to serve that aim if we regularly preach fly-over "devos" in place of expositional proclamations. The word is worth significant preaching, and with too-short sermons we may inadvertently communicate that our preaching texts (and the Bible as a whole) is only superficially relevant and not eternally important.

So there are five reasons not to preach sermons that are too short. The solution, however, is not to regularly preach until you lose your voice or people are getting antsy. For nearly all of us who preach, there is such a thing as a sermon that is too long. Thus:

Your sermons shouldn’t be too long, because . . .

1. Overly long sermons often dilute the substance of meaningful exposition.

My diagnosis for too-long sermons is usually that the preacher is trying to do too much. You don't have to say everything the text brings to you in your preparation. A judicious self-editing is one of the preacher's best tools. If your sermon is too long, it's likely that you are distracting people with rabbit trails, soapboxes, varying perspectives on the text that might be more sufficient for a commentary than a sermon, etc. Remember that the sermon is a different animal than a systematic theology text. Putting too much into your sermon can also rival the centrality of Christ and his gospel in your preaching of a text. Every lengthy bit added begins to rival every other lengthy bit, and suddenly the meat of the exposition and the heart of the gospel gets covered up in too much fat. It's possible, preacher, that you may be trying to do too much.

2. There is such a thing as fatiguing people’s ability to receive information.

Just as it's not good to accommodate people's short attention spans, it's also not good to test their endurance! This is my primary problem with sermons that have way too many points. (Please forgive that this blog post has ten points!) People have a limit when it comes to downloading information, and every point you have weighs against the other points. If you have points within points, "wheels within wheels," you begin to tax people's ability to "track" with your sermon. You may also be testing the resilience of their bladders and backsides! But in general, the longer your sermon, the more you venture into the arena of hearer fatigue wherein people lose their ability to retain what you've delivered.

3. The aim of a sermon is worship, not exhaustive knowledge.

Similar to what I said under number one, remember what the aim of a sermon is. As Ray Ortlund says, "A sermon is not a lecture. It is an encounter with the living Christ." The aim of the sermon, then, is not primarily information transfer — it is that, but it is more than that! — but rather devotional adoration of God through Christ. So the purpose of the sermon should not be to say everything you can say about a text but to say what is most pressing from the text and for the given moment in exalting, commending, and glorifying Christ.

4. It is better to leave people wanting more than wishing there’d been less.

Not that George Costanza knows a biblical sermon from the Adam you might be preaching about, but his wisdom is applicable here: Go out on a high note. That's hard to do if you're going on and on and don't know how to quit. Many sermons are too long for lack of knowing how to land the plane. If you routinely find yourself looking at the clock in the back of the room and realizing you need to rush your final point(s), you're probably doing too much. (Or not allotting enough time for the sermon; see the first five points.) Think enough of your congregation to give them the blessing of wishing the sermon had been longer, not shorter.

5. You’re probably not that good a preacher.

Okay, bottom line — and I'm sorry to end on a downer — you're probably not a great enough preacher to sustain people's attention and exhilarate them in grace with a sermon that approaches the one-hour mark. It's just the reality you and I face. The number of guys good enough to regularly preach for an hour in a fruitful way is pretty low, I reckon, and you and I (probably) aren't in it.

So what's the sweet spot? How long should a sermon be? My opinion, such as it is, is that most Sunday morning sermons should probably land in the 30-40 minute range. The sweet spot is probably 35 minutes, and much shorter or much longer than that ought to be exceptions.