What is yours and why? Please no replies saying the Bible, as this is not the answer to the question I have asked. Books need to be tested by the word of God, but books are writings of teachers whom have been given to the church to teach the saints. If in doubt read the books of Romans, and Ephesians to learn about spiritual gifts. Mine is Who are you to Judge by Erwin Lutzer. I prefer it as its very very practical. MacArthur's book Reckless Faith seems more of a read someone would do in seminary and it is not very practical. My favorite survey of false religions and cults book is So whats the Difference? Its more detailed than most websites & blogs, but not too technical and detailed. The book is very compact and about as thick as the Lutzer book I mentioned. I have recommended both books to many.