Here is an interesting observation from one whose interest and experience has included the stage (including a college degree in acting):
“I think [preaching] is probably a lot like acting. When someone asks me, ‘How did you memorize all those lines?’ I come away feeling like I must not have done a good job. They focused on the craft, not on the message. I think it was David Mamet (an American playwright) who said that if an audience comes away from a show talking about their lives and NOT about how the actor performed the role, then you know the actor did a good job.”
So, she goes on to point out, when after a sermon people spend the time talking about the impact of the message in their personal lives, the preacher has done what he set out to do.
That is a high challenge.
[Thanks and credit to Eva.]