Sermon Plagiarism: The Result of a Need to Entertain Instead of Inform?

Like the team at "Theology of the Body", I'm amazed by the amount of theology that was put into the sermons by Edwards and Augustine. What's even more amazing is the amount of theological terms that were used without explanation. The people listening to these sermons must have known the definitions of the terms being used.

When I read George Marsden's biography of Jonathan Edwards I was struck by how seriously everyone took religion in those days. Even in my church, which likes to pride itself for being Reformed, there are a lot of people who want just "practical" sermons, and not a lot of theology.