If a man has some spiritual gift and feels compassion for those who do not have it, he preserves the gift because of his compassion. But a boastful man will lose it through succumbing to temptations of boastfulness.
That’s why you should not become a disciple of a person who praises himself, in case you learn pride instead of humility.
Do not grow conceited about your interpretations of Scripture, lest your intellect fall victim to blasphemy.
Also, do not attempt to explain something difficult with contentiousness, but in the way which spiritual law enjoins: with patience, prayer and unwavering hope.
Vigils, prayer, and patient acceptance of what comes constitute a breaking that does not harm but benefits the heart, provided we do not destroy the balance between them through excess. He who perseveres in them will be helped in other ways as well; but he who is slack and negligent will suffer intolerably on leaving this life. A self-indulgent heart becomes a prison and chain for the soul when it leaves this life, whereas an assiduous heart is an open door.
Based on Saint Mark the Ascetic