Every passage has a primary idea supported by secondary ideas. Well-trained students of the Scriptures can distinguish between them. An expository sermon does not have to rest on a single passage, but careful exegesis is required of every passage used. If not, you will never know if you have reflected the passages accurately. A topical expository message is possible, but such a sermon is obviously easier to prepare when you have fewer passages. Second, the structure of the sermon must be consistent