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.
Pray before your body takes rest on your bed... If you are tempted, make the Sign (of the Cross) on your forehead reverently… for this is a known and tested weapon against the Devil.
Every tribulation reveals the state of our will, whether it inclines to the right or to the left. An unexpected tribulation is called temptation, because it subjects a man to a test of his secret dispositions.
He is not yet a faithful servant who bases himself on bare knowledge alone; a faithful servant is he who professes his faith by obedience to Christ, Who gave the commandments.
Having filled himself with pride, the Antichrist will begin to set himself up and glorify himself as God, belching forth slander against Christ. He will do this so openly that he will command that all those who do not want to serve him as God be killed.
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.
The grace of the Spirit is one and unchanging, but energizes in each one of us as He wills. When rain falls upon the earth, it gives life to the quality inherent in each plant: sweetness in the sweet, astringency in the astringent; similarly, when grace falls upon the hearts of the faithful, it gives to each the energies appropriate to the different virtues without itself changing.
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.
Concerning fasting, do not grieve, as I have said to you before: God does not demand of anyone labors beyond his strength. And indeed, what is fasting if not a punishment of the body in order to humble a healthy body and make it infirm for passions, according to the word of the Apostle: 'When I am weak, then am I strong' (II Corinthians 12:10).
Leave off all evasions, bend your neck to humility and obedience, and you will receive mercy. If you practice with humility and obedience what you hear from the fathers, God will grant you His blessed help not only in the work you are doing, but will make all your works successful, for He protects the path of those who fear Him and watches their progress.