What is the main conflict in The Greatest Miracle in the World by Og Mandino?

The Greatest Miracle in the World is a self-help book based on the true experiences of Og Mandino when he met a ragpicker who changes his life. This ragpicker, Simon Potter, was a kind man who spent his retirement going around helping people to see that they are part of the living dead and guiding them back into the world of the living. Og visited Simon on many occasions, learning a great deal from him until the day he found a package on his desk that had a farewell message on it. Og went to Simon's apartment only to find out that Simon never lived there. The Greatest Miracle in the World is a mystical story about the life-changing events in one man's life and the answers to how the reader may too change their own lives.