Good sermon illustrations do at least two things: they make key concepts in the sermon easier to understand and easier to remember. The primary way they do this is by turning that which is abstract into something concrete. As someone once said, they turn your listeners’ ears into eyes and help them see what you’re saying.
For example, I’ll never forget how Rick Holland compared the fleeting nature of human existence to the steam coming off the top of a cup of coffee (in Ecclesiastes), or how he described temptation as sugar-coated poison (in Proverbs 5). First I heard, and then I saw. And even now, more than ten years later, I still understand and remember.
Expository Thoughts 
Posted by Greg Breazeale on December 17, 2008 at 10:21 pm
What are your thoughts on stories? I used to tell lots of stories ins sermons, but have really backed off. I dont think that the parables of Jesus are justification for preachers telling stories. We need to be telling his story, not ours. I try and use them sparingly. I love analogy though, it is quick and really sharpens the edge of words.
GB
Posted by Ian Hall on December 17, 2008 at 11:54 pm
Those are great illustrations that you have cited as examples. Thanks.
I think telling a story is fine IF it actually illustrates the point you are seeking to make. But I don’t think you should use too many. Illustrations are like sugar – use the right amount and they are just to the taste of the congregation but use too many and they will sicken.
Posted by Mark Hollingsworth on March 22, 2009 at 9:21 pm
I think there are many ways to illustrate and good sermon illustrations personalize Biblical truth. I agree that there should be a balance in the length and amount of illustrations in a sermon, but they do help. I like what Matt said about turning your listeners ears into eyes. Very good. Thanks for sharing.
Blessings,
Mark