Preach the word; be ready in season and out of season; reprove, rebuke, and exhort, with complete patience and teaching.  2 Timothy 4:2

What is the length of a good sermon? This is a theological conundrum (big word for “lots of arguments”) that has been debated for centuries.

It is also the number one topic discussed in cars after a sermon. You would think an after-sermon car discussion would be about content, but how many of you have had this talk: “Great sermon, but I fell asleep at 20 minutes?”

All agree to the importance of preaching and listening to sermons.

Paul told Timothy to preach “in season and out of season” but he didn’t define how long the sermon should be. Evidently, Paul trended toward longer sermons as we find him preaching in Acts 20 from sundown till past midnight with the result of Eutychus getting drowsy and falling out of a window to his death.

Fortunately, the Apostle Paul, preaching in the power of the Spirit, was able to pray for Eutychus and raise him from the dead. I’ve never had this power in my preaching, as once they fall asleep, they stay asleep.

I did have one man who fell asleep at five minutes into my sermon for years, and I must admit that I wished our sanctuary had a window where he sat.

Through the years of being blessed by and enduring many sermons, I’ve developed the Sleep-o-meter.

As I preach, I watch the audience, as I listen to others preach, I watch the audience – observing the point in length when the audience begins to fall asleep, starts looking around the sanctuary, begins turning on mobile devices, or getting on their knees in intercession for deliverance.

The Sleep-o-meter has produced these results:

  • Almost anyone can hold a church’s attention for 20 minutes
  • A 30-minute sermon is fine if anointed
  • At 40 minutes, even an anointed sermon runs into difficulty
  • At 50 minutes, the witnesses in heaven, spoken about in Hebrews 12:1, begin to yawn

My Sleep-o-meter findings are supported by solid scientific research:

The optimal attention span for an audience, i.e., the attention span that can be comfortably held by an interested human engaged in listening to a speaker, is not five to ten minutes. Instead, it is approximately twenty (20) minutes. In fact, it is slightly less, somewhere in the 18-to-20 minute span, but twenty minutes is a decent and practical rough idea. Some people can hold their attention even longer, but they are outliers. After 20 minutes, no matter how interested we are, our focus is depleted, and will, unless corrective action is taken, erode steadily until we literally aren’t listening any longer. Now, this does not mean that people will automatically focus for that amount of time. On the contrary, unless carefully guided, people will lose focus after just a few minutes — for instance, the aforementioned five minutes (quoted from a solidly scientific blog).

Through the years, I have made the mistake of thinking that my in-depth content, brilliant sermon illustrations, or charismatic personality could hold audiences for hours. I found that I was wrong, not only on the “holding attention” for hours, but also in an overestimation of the brilliance of my content, illustrations, and personality.

I have come to this conclusion:  When the Spirit moves, preach past midnight, but on a normal Sunday there is great risk in going over 30 minutes.