I'm in the midst of working through "Preaching and Preachers" by Martyn-Lloyd Jones. This book was initially a series of lectures that the doctor gave that you can listen to on Spotify. The audio lectures allow the listener to hear the dry humor of Lloyd-Jones that is not so apparent when reading. I came across the section (below) that sheds some pastoral insight onto preachers and the preparation of sermons. Now, Lloyd-Jones doesn't actually say "plagiarize" in this section or in the entire book. But if you read what he's describing the point is clear- pastor's should write and preach their own sermons.
Some of the sub-text to the plagiarism controversies (I'm not thinking of any one in particular, but several in general) that have been popping up lately has been on giving a pass to men who preach other men's sermons. They say that if it wasn't for the internet, no one would have known that the sermon was "borrowed" from someone else. I think the quote below challenges that notion. People talk. The person in the pew is not so simple minded they can't figure these things out. If you are preaching what someone else labored to create, be sure of this, when people find out you will lose credibility.
Excerpt below is from D. Martyn Lloyd-Jones, Preaching and Preachers, Zondervan: 1971. Pages 180-181.
What is the purpose of all this reading? I reiterate that the object of all this reading is not primarily to get ideas for preaching. That is another terrible danger. As men tend to read their Bibles in order to get texts for sermons, so they tend to read books in order to get preaching material. I would almost describe this as the occupational disease of the ministry. I remember a minister telling me in 1930 that he had been to a conference, or house-party designed to deepen people's spiritual experiences. He told me of the great benefit he had derived from the conference. I was expecting him to tell me something about what he had experienced, or of what it had meant to him spiritually; but that is not what he told me. He said, 'I got wonderful preaching stuff there.' Preaching stuff! Preaching material! He did not go to the conference to derive spiritual benefit, but simply to get material-illustrations, stories of other people's experiences, etc-for his sermons. He had virtually immured himself from any spiritual influence because he approached everything in this way. He had become a professional. He would read his Bible to get texts, he would read books to get ideas and so on.
In fact this can become quite ludicrous; and I am glad that this is so for this reason, that preachers who have to go to books to get sermons are generally caught out! This was brought home to me when I lived in South Wales. There was a famous religious bookshop in a certain town, and preachers from the outlying district used to go into the market and to visit the bookstall once a week or oftener. They all went to this bookshop and bought the various books. The tendency was, naturally, for all to buy the same books, and the result was that many of them were preaching the same sermon! But, unfortunately for them, their people, their church members, knew one another and when they met they would talk about their respective churches and ministers. One would talk about a wonderful sermon he had heard the previous Sunday. 'What was the text?' the other would ask. On being told the questioner would begin to smile, because he had also been listening to much the same thing. There were slight variations of course, but essentially it was the same sermon! These poor men had become dependent upon books for their ideas.
I remember another minister, who was a good preacher, telling me on one occasion when I happened to be travelling in the same compartment in a train and found him reading Robert Bridges' Testament of Beauty that he 'got' much more from 'these fellows' than he did from anybody else. What he meant was that he got more ideas and preaching material there. There are men who get their ideas from books and journals, indeed from all sorts of strange places.