We preachers are all prone to use family events and incidents to illustrate our sermons. The dumb spouse is second only to the idiot adolescent child in making his or her meandering way through the fertile fields of homiletics. It is easy to eisegetically snuggle a good spouse into a Corinthian passage on how women ought to behave, but it is not fair! Even if you ask your spouse for permission, you sin with the practice. The fact that you have to ask permission probably says you're pretty sure this kind of sermon inclusion is off-track. Even the asking of it sounds as if you're saying, "Is it OK, Darling, if I exhibit your idiocy in my sermon this week? It would mean a lot to Jesus."
I want off this thumb-worn issue in favor of a more insidious kind of abuse. I have a lay friend who loves to teach. He is very big on the Civil War and often takes part in Civil War battle reenactments. He's a fair Bible teacher, but he is an indefatigable historian because this is his passion. So no matter what he is teaching, it all ends up at Manassas. He amazes me that, with a bit of gyration, he can snuggle Gettysburg into Philemon. When it is all over, I can't remember exactly how he did it, but I know he did.
Most of us who preach pursue some kind of hobby or field of learning, and without realizing it we can make our pursuit part of our sermon. I like prophecy in general, but I am suspicious of it when it becomes too specific. I have known prophecy-loving preachers who feel compelled to help me understand Gog and Magog, even when they are preaching the Book of Ruth. They just can't help it. Ruth and Boaz are fairly easy to write into prophecy; after all, the pair lived in Bethlehem, directly south of Moscow, from whence shall come the hordes of invaders in the last days.
For some preachers, their sermons keep close company with professional football. I had a pastor who just before the Rams' game in Los Angeles, quoted in his sermon a word of support for his favorite team (which wasn't the Rams) by citing Daniel 8:7: "I saw him attack the ram, furiously shattering his two horns, and the ram was powerless to stand against him." You actually have to look on down in the chapter to Daniel 8:20 to find out the ram in Daniel's sermon is Media and Persia and has no direct correlation to the NFL.
In Alabama, home now to two championship teams—Bama and Auburn—these two rivals have developed fierce antagonisms, and their relative merits have wound up in sermons of all sorts. The Auburn team serves the sermon with a sort of mixed metaphor, as it is alternately called the Tigers or the War Eagles, but there are easy ways to work Eagles into a sermon: They that serve the Lord shall mount up with wings as War Eagles, sort of (Isa. 40:31). Where the War Eagles are gathered together there shall the carrion be, kinda (Matt. 24:28).