Self-knowledge is according to the teaching of St. Basil the Great of major significance for the spiritual life. The Christian who understands his nature, needs and destination can assess the real value of the material goods, which are useful but temporary, and that of virtues and spiritual goods, which are eternal and lead to salvation. Moreover, he acknowledges his weaknesses and sins, which helps him in spiritual struggle and repentance. Finally, self knowledge protects human from falling into desperation, when hefaces serious difficulties in life, and prevents arrogance, when he experiences prosperity.