One of the best little articles I've ever read on preaching is found in The Art and Craft of Biblical Preaching. The title of the article is "The Danger of Practical Preaching: Why People Need More than the Bottom Line." The author, Lee Eclov, writes:
The Bible spends much more time on shaping the spiritual mind than commanding particular behavior. We need far more training in the ways of grace, of spiritual perceptions, and of what God is really like than we do on how to communicate with our spouse. Understanding the glory of Christ is far more practical than our listeners imagine. Properly preached, every sermon based on a passage of Scripture is fundamentally practical. Every author of Scripture wrote to effect change in God's people. It is our job as preachers to find the persuasive logic of that author and put that clearly and persuasively before our people through biblical exposition.