It is quite obvious that one of the most powerful means for acting on the body is faith. People who have a simple heart, not a very complicated mind – simple people, you see – who don’t have a very great, very complicated mental development but have a very deep faith, have a great power of action over their bodies, very great. That is why one is quite surprised at times: “Here’s a man with a great realisation, an exceptional person, and he is a slave of all the smallest physical things, while this man, well, he is so simple and looks so uncouth, but he has a great faith and goes through difficulties and obstacles like a conqueror!”
Ref: Questions and Answers 1957-1958