The chapter of The Purpose-Driven Life that the gal read to him was about how "you were created to serve God." Divorced from the context of the rest of the book, that statement is consistent with Islamic theology (which is about as ridgidly predestinarian as any Calvinist Christian).
Divorced from the rest of WHAT book? The whole Purpose Driven phenomenon is divorced from the rest of THE BOOK and is consistent with any theology you want to make it as long as you say the name Jesus once in a while and GOD even more often.