I have mixed feelings about stopping on time. I am very defensive of the preacher who needs a few more minutes to complete the case he is building on the Lord’s behalf. On the other hand, I am sympathetic with the folks who have another commitment soon after the time they reasonably assume the service should end.
When I was just getting starting in the pastoral ministry, I had the attitude that I would just preach until I got finished, and that people ought to just sit there and listen until I did. I said that to a pastor of a much larger church, and he said, “If you ever preach on TV, you’ll quit on time, or they’ll cut you off.” I began noticing some TV preacher that I considered to be very good preachers, and they never got cut off in the middle of their sermon, they brought it to an effective end just as their air time ended. I realized that the Holy Spirit can work through planning. It is not unspiritual to know what you are going to say, before you get up to say it.
On the Day of Pentecost, they had prayed for seven days, they preached for three minutes, and three thousand people got saved. There may be a lesson in there, that you need to pray more, and you don’t have give people an endurance test with your preaching. Even the Apostle Paul put Eutycus to sleep, when he preached on and on. I really don’t want to put them to sleep.