If you know the truth then why don't you say the answer in simple term's.. what you will do if non muslim ask's the same question with you ? if you ask him to read 79 pages note book then it will be very difficult for him to understand this issue.. If non muslim ask's us what is islam then we cant say him go and read quran, and all valid ahadith.. we have to answer him in simple term's so that he should not be confused right ? we cant ask every one to read this book.. if someone has asked simple question means answer should also be simple to understand.. Repeating the question, answer me in simple if you know the truth.. Why to follow only one imam if all four imam's are correct ?..