When we misuse the soul’s powers their evil aspects dominate us. For instance, misuse of our power of intelligence results in ignorance and stupidity; misuse of our incensive power and of our desire produces hatred and licentiousness. The proper use of these powers produces spiritual knowledge, moral judgment, love and self-restraint. This being so, nothing created and given existence by God is evil.
St. Maximos the Confessor
Wisdom and prayers of saints 