In his latest book, Counterfeit Gods, Keller discusses what the book title suggests. He deals with the problem of false gods in our lives, what these false gods tend to be, and how to deal with false gods from a biblical perspective.
A couple of Keller's statements stand out to me:
"Idols capture our imagination, and we can locate them by looking at our daydreams. What do we enjoy imagining? What are our fondest dreams? We look to our idols to love us, to provide us with value and a sense of beauty, significance, and worth." (page xxi)
"Is there any hope? Yes, if we begin to realize that idols cannot simply be removed. They must be replaced. If you only try to uproot them, they grow back; but they can be supplanted. By what? By God himself, of course. But by God we do not mean a general belief in his existence. Most people have that, yet their souls are riddled with idols. What we need is a living encounter with God." (page 155)
This book is pleasant to read and will challenge your focus in life. I recommend it.