I plan to read C.J. Mahaney's Worldliness in the next few weeks. Right now I'm finishing a series of sermons delivered at Covenant Life Church on what it means to be in the world and not of it. I've been told Mahaney's book was developed largely from those sermons.
As I've listened to them, I've been struck by how much these pastors are leading their congregation to weigh the same kinds of worldliness issues any church in the fundamentalist orbit would. Perhaps I'm oversimplifying or my memory fails, but it seems to me that the only meaningful issues difference is that Kauflin dismisses as ridiculous the notion that a rhythm with an off beat is innately carnal.
What's really striking is how consistently Mahaney, Kauflin, and Harris circle back to deal with heart issues. Especially Mahaney. So we hear him saying, "Any biblical discussion of modesty begins by addressing the heart, not the hemline." He asks his church to consider internal priorities and motivations and values—the kinds of questions that aren't likely to create universal standards or binary decisions, but are designed to help believers understand the condition of their own hearts.
Seems as though there's a big difference between that and "I can tell a lot about how spiritual a guy is by the length of his hair," or "Am I telling you that because my wife and daughters don't wear slacks that you shouldn't either? Yes, that's exactly what I'm telling you!" (True stories, both of them. Somewhere out there are about a thousand of you who heard the latter.)