How to spot "approved" false prophets

Why do people fail? Unfortunate circumstances? Sometimes. Poor training and lack of experience? Sometimes. Lack of sufficient finances? Often.
The famous self-help book Think and Grow Rich, by Napoleon Hill, lists 30 reasons why people fail. His list includes these four reasons. However, he did not identify one prominent reason for failure, following faulty leaders. Following faulty leaders? Yes, many times, and more than we want to admit.