Just coming at this from another angle, but one I’ve touched on before:
“Listeners are impressed with, and helped by, a blast of Scriptural cross-referencing diversity – it breeds confidence, assurance, awareness and whole-counsel-health.”
This thinking is fairly common. Preachers assume that listeners will benefit from multiplied cross-referencing because it will give them confidence in the preacher’s knowledge, assurance of biblical truth, awareness of the big picture of the canon and health from receiving the whole counsel of God.
I do not want to say that the preacher should only ever preach from a single text and never cross-reference. There are times when it is helpful. For instance, if the main idea of the preaching text seems unusual, it may help to show the same idea elsewhere in the Bible. For another instance, if the main preaching text is built on, or anticipates another biblical passage, it may be helpful to go there and show the link.
Also there are times when the message is built on multiple texts, as in a topical exposition, or when the message is tracing a biblical theme.
But there is a difference between a message that picks off key passages like an accurate sniper and a message that feels like the preacher has hacked off the barrel of their concordance and aggressively pulled the trigger in your direction.
1. Listeners gain confidence in the preacher through the quality of Bible handling, not the quantity of texts momentarily touched. Imagine being taken into a new city. Would you prefer a knowledgeable guide who takes you to a particular point of interest, or even a select few, and then introduces you carefully and accurately to their history and significance. Or would you prefer to drive around the city at break-neck speed with shouts of, “and there’s a house! And there’s a phone-box-thingy! Another house! That’s the place that so and so had something to do with! Another house! Town hall! House! . . . etc.”? The latter approach tires people out, overwhelms them, and by no means generates confidence in the tour guide’s knowledge.
2. Listeners gain assurance of biblical truth by probing a text well, rather than briefly touching on multiplied texts. Even if there is a need for a quick survey to underline a truth, it is a truth seen by careful consideration of a primary text.
3. Awareness of the whole canon comes from a tour of selected highlights that is reinforced carefully, rather than from a snapshot of texts wrenched from context.
4. Health does not come from a shower of vitamin pills, but from properly digesting a good balanced diet. Give the listeners the whole counsel, but don’t just shower them with biblical cross-references every week. They need to be able to digest what they are taught. Since explaining and applying the text takes time, why steal from explanation or application by filling the message with the sideways energy of unnecessary cross-references?
As a default, stick in your text and preach it better, your listeners will be grateful and healthier as a result. When you need to cross-reference, do so on purpose and judiciously.