Observe your thoughts, and beware of what you have in your heart and your spirit, knowing that the demons put ideas into you so as to corrupt your soul by making it think of that which is not right, in order to turn your spirit from the consideration of your sins and of God.
When you intend to do something and see that your thought is perturbed, and if after invoking God's Name it remains perturbed even by a hair's breadth, know from this that the action you mean to commit is from the evil one and refrain from commiting it. For nothing done with perturbation is pleasing to God.
There is nothing more efficacious against the wiles of the devil, dearly beloved, than the kindness of forgiveness, and the bountifulness in charity, by means of which sin is either avoided or overcome.
When anyone is disturbed or saddened under the pretext of a good and soul-profiting matter, and is angered against his neighbor, it is evident that this is not according to God: for everything that is of God is peaceful and useful and leads a man to humility and to judging himself.
To act 'according to one’s strength' means to use a little less than necessary both of food, and drink, and sleep... As for food, restrain yourself when you wish to eat a little more, and in this way you will always make use of it moderately.
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.
Silence of lips is better and more wonderful than any edifying conversation. Strive to acquire humility and submissiveness. Never insist that anything should be according to your will, for this gives birth to anger. Do not judge or humiliate anyone, for this gives birth to anger. Do not judge or humiliate anyone, for this exhausts the heart and blinds the mind, and thereon leads to negligence and makes the heart unfeeling.
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.
The incessant invocation of God's name is a medicine which mortifies not just the passions, but even their influence. Just as the physician puts medications or dressings on a wound that it might be healed, without the patient even knowing the manner of their operation, so also the name of God, when we invoke it, mortifies all passions, though we do not know how that happens.
Accordingly, a man will neither be puffed up through pride, nor cast down by despair, if he uses the good things divinely bestowed on him, to the glory of the Giver; withholding his desires from the things which he knows will hurt him. And so he that would preserve himself from the wickedness of envy, from the corruption of sensuality, from the unrest of anger, from the desire of revenge, will be purified by the sanctifying power of true abstinence, and will taste the joy of imperishable delights, so that by making spiritual use of them, he will learn to change earthly possessions into heavenly, not by storing what he has received, but by multiplying more and more that which he has been given.
The nature then of Christ's teaching is attested by His own holy statements: that they who wish to arrive at eternal blessedness may understand the steps of ascent to that high happiness. 'Blessed,' He saith, 'are the poor in spirit, for theirs is the kingdom of heaven.' It would perhaps be doubtful what poor He was speaking of, if in saying 'blessed are the poor' He had added nothing which would explain the sort of poor: and then that poverty by itself would appear sufficient to win the kingdom of heaven which many suffer from hard and heavy necessity. But when He says 'blessed are the poor in spirit,' He shows that the kingdom of heaven must be assigned to those who are recommended by the humility of their spirits rather than by the smallness of their means.
