One of my preaching professors had us do a great exercise. She told us it was Sunday morning, twenty minutes before the service started, and we had scheduled a guest preacher for today, who had just called to say he was in the emergency room of the local hospital with his wife who was having an asthma attack, and he wouldn't be able to be there. We had to come up with a sermon in twenty minutes, with no commentaries, no Web access, only our Bibles and our brains.
We then had to preach our sermon to the class.
She handed each of us a scripture citation, put twenty minutes on the timer, and said "Go!"
You want to talk panic?!
Well, each of us had something to say when we got up there, all right. Some of us more than others.
I started off quite well, went places with it, and wound up for the great resounding climax--only to fall flat without a firm conclusion. I sputtered around for a few moments, and finally said, "In all God's many names, amen. Will you please rise and join together in our response hymn?"
So now I always make sure I have something great for an ending. I figure even if the rest was not so hot, if the ending is knock-out, the congregation will remember that and forget about the rest...
All of which is to say that I'm preaching from an (extended) outline tomorrow, but I wrote out the final paragraph so I don't ruin the effect (if any) of the rest of the sermon, or else that I end it coherently at least (depending on how the beginning and middle are!).
PS The prof was feeling kindly; I got a B+.