Because I occassionaly preach, these two quotes stood out when I read them this week.
With a sermon, the same structure would be used with the addition of another old saw. A joke, a quote, an illustration and a prayer. The prayer serves as an additional conclusion, in which the preacher again summarizes the main points and the thesis under the guise of an address to God. The problem with the formula is that it is a formula. The problem with a formula is familiarity. Familiar is good if the desired effect is to make the people feel comfortable. Making the people feel comfortable is not a sermon. A sermon can comfort people, but should never make them feel comfortable. This is an important difference.
-Post Rapture, How many points should a sermon have?
It was because Christian preaching does not need elaborate refinement of verbal expression that fishers, who were uneducated, were chosen to preach the gospel. In that way the truth of the message would be its own recommendation, and it would not depend on the cleverness or ingenuity of human wisdom.
-Ambrosiaster (4th century), Commentary on Paul’s Epistles. Quoted in Ancient Christian Devotional.