You will see a book often referred to here called "Releasing the Bonds : Empowering People to Think for Themselves" ... you have to treat him very carefully, this is a cult, if he believes it is true he will become very defensive, you should try to find subtle ways to get him to think and question, the book mentioned is a great tool in this process for you, not for him, to read.
http://www.amazon.com/Releasing-Bonds-Empowering-People-Themselves/dp/0967068800