“Any trained public speaker can select a theme and gather a bundle of stories that will touch an audience emotionally, but this is not preaching.” (Chappell, 200.) We need to remember always that an illustration is there to serve the sermon, to aid in clarifying explanation, support, or application, but not to substitute for sound explanation.
If you suspect that a message might be too illustration-heavy (a rare problem for some preachers), then it is worth going through the message and questioning the purpose of each one. Is it there to clarify explanation, to support a point, or to apply the teaching in real life imagery? Or is it there because you really want to tell it, or because you know they’ll enjoy that one? Be ruthless in filtering illustrations so they are genuinely serving the sermon.
If people perceive you to be a preacher who just tells stories, then your credibility will be damaged. Be sure the illustrations are the servants, not the focal point of your preaching.