I am currently reading this book by D.A Carson and loving every page of it. The battle over worship (which should actually be clarified as music), is one that I have been in on both sides of the fence. I will post my thoughts on the book later, but Challies has a great post on his take and how it related to some popular modern worship songs.
These songs go beyond the Jesus is my girlfriend lyrics (except maybe in the secret), to really not expressing anything (except maybe procrastination).
You can read it HERE