Object: a yo-yo (might want to get a young person with yo-yo skills to help with this demonstration)
Good morning, boys and girls. Have you ever played with a yo-yo? They're a lot of fun once you learn how to play with them. You can do all kinds of tricks with a yo-yo, but first you've got to learn the most basic move: getting the yo-yo to go up and down. That's the first and most important move for the yo-yo, just going up and down. That's what a yo-yo was made to do.
Did you know that sometimes our faith can be like a yo-yo?…
Dynamic Preaching, Collected Sermons, by King Duncan