Summary: Occasionally a preacher is required to give a sermon with only a few minutes notice and completely without preparation. Here's how to do it.
Learn how to preach without notice.
2 Timothy 4:2 tells preachers to always be ready to give a sermon. There comes a time when you will show up at a church service only to be asked to pinch hit for someone else who had been scheduled to speak. Perhaps you are on vacation and visiting a church in a different town, and are offered the sermon slot for the day. It happens! How do people do it? In the sermon on preaching without notes, we learned how to preach extemporaneously. Now it's time to crank the ratchet up one more notch and discuss how to preach impromptu, without notice or forewarning.
We will look at how to give an impromptu sermon, starting out with the spare sermon, then moving on to the special request, the extraordinary request, the exegetical request, the topical request, preparing for the unprepared ahead of time and end up with a few general pointers.
1. The Spare Sermon
Most preachers have a spare sermon or two up their sleeves so to speak. Look at some preacher's Bibles and you will discover the notes for a few spare sermons hidden away in the back. Some preachers even have a few standard sermons that they have polished for years and are ready to give at a moment's notice. That is certainly one way to be always ready to preach. However, the spare sermon is not always the right answer for a particular situation. Sometimes, it just does not fit the need of the hour. There are other techniques that can help as well.
2. The Special Request
Every preacher has had some experiences which they may be called upon to testify about or report on. It may be a mission trip, a church camp, a specialized ministry, an area of expertise such as the understanding of a particular doctrine or ministry process. Someone who is a church planter or a worship leader for instance, may be called upon at any time to explain some principles relating to that specialty. Usually, in such cases, the subject matter is not a major problem. All the preacher has to do is organize a few thoughts to make a logical flow. We will discuss that a little later.
3. The Extraordinary Request
Sometimes unexpected events such as a sudden death, tragedy, emergency, cause for celebration, or other events good or bad can create a request for a preacher to speak impromptu in an area where the subject matter may not be as familiar. This is perhaps the hardest impromptu to give. Yet, even here, a few moments forethought can help greatly.
4. The Exegetical Request
This is often an easy impromptu to give because, as we covered in previous lessons, the points of the sermon can be easily found in the text. The difficulty here is whether or not you are able to pick the text or are given one. Knowing a little about the text already can be a great help. If you are totally unfamiliar with the text, thinking out loud on your feet, can help the audience actually see the mental processes that one should go through in analyzing a text. You can actually say out loud that the best way to analyze a text is to begin with certain steps, such as context, natural reading, historical background (if you know it) and so on.
If you are unable to answer a particular question about the text, that can also be good. People need to understand that some questions will remain unanswered and that forcing an answer into a text is bad. So, saying that the information in the text does not allow you to answer the question, unless there is something you are missing, can be an excellent example of dealing honestly with the text of Holy Scripture.
If you are able to answer a particular question about the text, that is just as good. Here you need to explain why the text answers the question. Explain the logic behind your answer. If you know some of the Greek or Hebrew from earlier research, that will help, but if you don't say so. Say that you'd like to do more research into the text. However, if there are several answers, say that too. Help people to realize that being ambivalent about a text of scripture is not being wishy-washy, but being honest. Sometimes, being dogmatic can be dishonest.
5. The Topical Request
If you are asked to preach on a topic, such as a tragedy, or a blessing, that is fine as well. There are some simple rules which we will discuss later, that can help here. However, if you can think of a fitting scripture that also explains the topic, use it by all means. Make sure that you are following all the rules of good exegesis and not cramming an unsuitable text into an only somewhat related topic. If however, there is a common principle that the text and the topic have, that can be good to use.