If you wish to be saved and 'to come unto the knowledge of the truth' (I Tim. 2:4), endeavor always to transcend sensible things, and through hope alone to cleave to God. Then you will find principalities and powers fighting against you (Eph. 6:12), deflecting you against your will and provoking you to sin. But if you prevail over them through prayer and maintain your hope, you will receive God's grace, and this will deliver you...
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.
There is a sin which is always 'unto death' [1 Jn 5:16]; the sin which we have not repented. Even a saint's prayers will not be heard for the unrepented sin. The person who repents correctly does not imagine that his sins are cancelled through his own effort; but knows that through this effort he makes peace with God.
BROTHER: Behold, through what have the men of old triumphed? OLD MAN: Through the fervor of their supernatural love, and through the death of the corruptible man, and through the contempt for pride, and through the abatement of the belly, and through the fear of the judgement, and through the promise of certainty; through the desire for these glorious things the fathers have acquired in the soul the spiritual body.
Anger is by nature designed for waging war with the demons and for struggling with every kind of sinful pleasure. Therefore angels, arousing spiritual pleasure in us and giving us to taste its blessedness, incline us to direct our anger against the demons. But the demons, enticing us towards worldly lusts, make us use anger to fight with men, which is against nature, so that the mind, thus stupefied and darkened, should become a traitor to virtues.
And the old man also said, 'God saith unto thee thus -- if thou lovest Me, O monk, do that which I ask, and do not that which I do not desire. For monks should lead lives wherein they act not in iniquity, and a man should not look upon evil things with his eyes, no hear with his ears things which are alien to the fear of God, nor utter calumnies with his mouth, nor plunder with his hands; but he should give especially to the poor, and he should not be unduly exalted in his mind, and he should not think evil thoughts, neither should he fill his belly. Let him do then all these things with discretion, for by them is a monk known.' The old man also said, 'These things form the life of a monk: good works, and obedience, and training. A man should not lay blame on his neighbor, and he should not utter calumnies, and he should not complain, for it is written, 'The lovers of the Lord hate wickedness.'
Keep your mind from malicious thoughts of your neighbors, knowing that such thoughts are hurled by diabolical power, to keep your mind from your own sins and from seeking.
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.
Whether you pray with brethren or alone, try to pray not simply as a routine, but with conscious awareness of your prayer. Conscious awareness of prayer is concentration accompanied by reverence, compunction and distress of soul as it confesses its sin with inward sorrow.