Failure is due to the domination of the false self. It alone puts out the thought of failure, of weakness, of limitation. It is not capable of sustaining concentration or effort. When one has controlled this self and its passions, and especially when one has performed the spiritual practices which link one to God, the True Self, one has conquered this false lower self.
This is the great victory of life. All other victories are unimportant in comparison with it and not essential to mundane existence. Once the nufs is mastered, the key to every success is at hand. This is conveyed in the allegory of "The Thief of Baghdad."