When the central being has made its surrender, the chief difficulty has disappeared. The outer being is like a crust. In ordinary people the crust is so hard and thick that they are not conscious of the Divine within them. Ambition has been the undoing of many Yogis. That canker can hide long.
Many people start on the Path without any sense of it.
But when they get powers, their ambition rises up, all the more violently because it had not been thrown out in the beginning. A story is told of a Yogi who had attained wonderful powers. He was invited by his disciples to a great dinner. It was served on a big low table. The disciples asked their Master to show his power in some way.