The Lord commands all men to repent (Matt. 4:17), so that even the spiritual and those making progress should not neglect this injunction and fail to give attention to the smallest and most subtle errors.
The lower you descend, the higher you ascend; and when, like the psalmist, you regard yourself as nothing before the Lord (cf. Ps. 39:5), then imperceptibly you will grow great. And when you begin to realize that you have nothing and know nothing, then you will become rich in the Lord through the practice of the virtues and spiritual knowledge.
Those who have sinned must not despair. Let that never be. For we are condemned not for the multitude of evils, but because we do not want to repent...
He who reveres the Lord does what is commanded, and if he commits some sin or disobeys Him, endures whatever he has to suffer for this as being his desert.
When tested by some trial you should try to find out not why or through whom it came, but only how to endure it gratefully, without distress or rancor.
In patience is the assembly of all the virtues by which our souls are saved, as St. Ephraim says: He who acquires patience touches on every virtue; for he rejoices in sorrows, is well tested in misfortunes, is glad in perils, is ready for obedience, is filled with love, gives praise when provoked, is humble when reproached, is unwavering in misfortunes.
When someone is beginning the spiritual life, he should not study a lot, but instead watch himself and guard his thoughts. A strong person is the one who chews well, not the one who eats a lot.
Reprimand without feeding thine own self-love, considering whether thou wouldst be able to bear what thou demandest of another... It is of greater benefit for the soul to acknowledge itself to be guilty of everything and the last of all, than to resort to self-justification, which hath its origin in pride: God opposeth the prideful, but giveth grace unto the humble.
St. John Climacus was asked if there are reliable signs by which it's possible to know whether a soul is drawing near to God or moving away from Him. After all, regarding ordinary things there are clear signs as to whether they're good or not. When, for instance, cabbage, meat or fish begins to rot, it's easy to notice it, since the rotting object begins to give off a foul odor, the color and taste change, and its external appearance witnesses to its deterioration. Well, and what about the soul? After all, it's bodiless and can't give off a bad smell or change its appearance. To this question the Holy Father replies, 'A sure sign of the deadening of the soul is the avoidance of church services.'