In his book Preparing Evangelistic Sermons (Baker), Ramesh Richard talks about the importance of illustrations in the evangelistic sermon: “An evangelistic sermon desperately needs illustrations—and in greater numbers and of higher quality than post-evangelistic sermons. Our Lord and his Word profusely employ profound illustrations—story, narrative, humor, questions, even one-liners—to communicate truth. Illustrations help the audience avoid misunderstanding content, distraction in thought, tedium in active listening and a quick disposal of truth…
“Clear understanding of content forms the basis for acceptance or rejection of the gospel. It is better for the listeners to understand and reject your point and accept it without understanding it. Your illustrations provide staying power for serious subjects such as the holiness of God, personal sin, the uniqueness of Jesus, and the exclusive condition of faith. They also provide relief for the audience (and you) during the intensity of proclamation. Illustrations, especially from personal life, authenticate your humanness. A vulnerable preacher is a believable preacher.”