A sermon should be a bullet and not buckshot. Ideally each sermon is the explanation, interpretation, or application of a single dominant idea supported by other ideas, all drawn from one passage or several passages of Scripture.
Expository preaching is the communication of a biblical concept, derived from and transmitted through a historical, grammatical, and literary study of a passage in its context, which the Holy Spirit first applies to the personality and experience of the preacher, then through the preacher, applies to the hearers.
Preaching means, “to cry out, herald, or exhort.” Preaching should so stir a man that he pours out the message with passion and fervor. Not all passionate pleading from a pulpit, however, possesses divine authority. When a preacher speaks as a herald, he must cry out “the Word.” Anything less cannot legitimately pass for Christian preaching.
Accuracy, not to speak of integrity, demands that we develop every possible skill to keep us from declaring in the name of God what the Holy Spirit never intended to convey.