You don't have to agree with him, but don't read the book if you have already made up your mind about him. Personally, when I read the book I was focused on the book not the author and that really helped me understand what he is actually saying and not what "I think he is saying".
If you can put aside your "personal" feelings about the guy & focus on "what" his message is (which I think is the best way of reading a book & listening to people) then I promise you, you will have a blast.
