Twenty-five things about preaching you can't learn in school about the preacher, about the truth, about sermon preparation, about illustrations, and about the message.
"Preach the word; be ready in season and out of season; reprove, rebuke, and exhort, with complete patience and teaching. For the time is coming when people will not endure sound teaching, but having itching ears they will accumulate for themselves teachers to suit their own passions, and will turn away from listening to the truth and wander off into myths. As for you, always be soberminded, endure suffering, do the work of an evangelist, fulfill your ministry." - II Timothy 4: 2-5