If you wish to be delivered from shameful passions, do not behave with anyone familiarly, especially with those toward whom your heart is inclined by a lustful passion; through this you will be delivered also from vainglory. For in vainglory is involved the pleasing of men, in the pleasing of men is involved familiarity of behavior, and familiarity of behavior is the mother of all passions.
If we desire to acquire faith the foundation of all blessings, the door to God's mysteries, unflagging defeat of our enemies, the most necessary of all the virtues, the wings of prayer and the dwelling of God within the soul--we must endure every trial imposed by our enemies and by our many and various thoughts... if we forcibly triumph over the trials and temptations that befall us, it will not be we who are victorious, but Christ, Who is present in us through faith.
When a man has been sufficiently illumined, however, to perceive his own faults, he never ceases mourning for himself and for all men, seeing God’s great forbearance and what sins we in our wretchedness have committed and still persist in committing. As a result of this he becomes full of gratitude, not daring to condemn anyone, shamed by the profusion of God’s blessings and the multitude of our sins. Thereupon he joyfully renounces everything in his own will that is counter to God, and he watches over his own senses, so as to prevent them from doing anything beyond what is unavoidably needed.
Condemn only yourself, and you will not be condemned at His second and awful coming. From your whole heart remit the sins of whoever sins before you, and your Father who is in heaven will remit your sins.
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.
All men are made in God's image; but to be in His likeness is granted only to those who through great love have brought their own freedom in subjection to God... Free will is the power of a deiform soul to direct itself by deliberate choice towards whatever it decides.
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).
Such are the souls of the saints: they love their enemies more than themselves, and in this age and in the age to come they put their neighbor first in all things, even though because of his ill-will he may be their enemy.
Endurance is like an unshakeable rock in the winds and waves of life. However the tempest batters him, the patient man remains steadfast and does not turn back; and when he finds relief and joy, he is not carried away by self-glory: he is always the same, whether things are hard or easy, and for this reason, he is proof against the snares of the enemy.
As wax cannot take the imprint of a seal unless it is warmed or softened thoroughly, so a man cannot receive the seal of God's holiness unless he is tested by labors and weaknesses. That is why the Lord says to St. Paul: 'My grace is sufficient for you: for My power comes to its fullness in your weakness'; and the Apostle himself proudly declares: 'Most gladly therefore will I rather glory in my weaknesses, so that the power of Christ may rest upon me' (2 Cor. 12:9).
Even a pious person is not immune to spiritual sickness if he does not have a wise guide -- either a living person or a spiritual writer. This sickness is called prelest, or spiritual delusion, imagining oneself to be near to God and to the realm of the divine and supernatural. Even zealous ascetics in monasteries are sometimes subject to this delusion, but of course, laymen who are zealous in external struggles (podvigi) undergo it much more frequently. Surpassing their acquaintances in struggles of prayer and fasting, they imagine that they are seers of divine visions, or at least of dreams inspired by grace. In every event of their lives, they see special intentional directions from God or their guardian angel. And then they start imagining that they are God's elect, and often try to foretell the future. The Holy Fathers armed themselves against nothing so fiercely as against this sickness -- prelest.