Do no application. Expositional preaching is preaching that takes the main point of a scriptural text, makes it the main point of the sermon, and applies it to life today. Good expositional preaching will apply the text specifically: to different kinds of people in different spiritual states and different situations in life.
Use no illustrations or stories. Expositional preaching that has little human interest will be dry and flat. Expositional preachers should judiciously use illustrations and anecdotes that illumine the text. This helps people understand a text more easily and relate it to their lives.
Give excessive exegetical detail. Sermons that discourse on genitive absolutes and passive participles will feel academic and lifeless. An expositional sermon should explain the text, but it shouldn’t seek to be an exhaustive, scholarly commentary.
Fail to set the text in its canonical horizon. Poor expositional preaching will attempt to explain a passage of Scripture without explaining where the text lies within the whole scope of Scripture and redemptive history. In order to truly explain a text you must explain how it relates to the rest of the Bible’s storyline.
Fail to connect the text to the gospel. The most important aspect of connecting a text to the rest of Scripture is connecting it to the gospel. All of Scripture points toward and explains the saving work of Christ (John 5:39). Fail to preach the gospel as it arises from the text and you’ve failed to communicate the point of that passage. Also, your sermon will quickly veer toward moralism.
Fail to preach the text with appropriate urgency and weight. God’s Word urges us to renounce our sin, warns us of coming judgment, calls us to trust in Christ, and demands our joyful obedience. Expositional preaching that doesn’t have appropriate urgency and weight detracts from the authority of God’s Word.