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.
Prayer is a branch (of a tree) of meekness, and freedom from anger. Prayer is an expression of joy and thankfulness. Prayer is a remedy against sorrow and depression.
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.
Go, sell all that belongs to you and give it to the poor and taking up the cross, deny yourself; in this way you will be able to pray without distraction.
Watch constantly, learning to understand God's law, for this warms the heart with heavenly fire. Guard your lips from the idle word, or empty talk, lest the heart gets used to evil words.
Always keep this in mind: you are not doing anything virtuous by your continence. Or can it be considered a virtuous act when a man who, out of his own carelessness, has been trapped deep down in a mine shaft, takes a pick and shovel and tries to work his way out? Is it not, on the contrary, quite natural for him to make use of the tools given him by a higher authority to make his way up out of the choking air and darkness? ...From this picture you can gain wisdom. The tools are the implements of salvation, the commands of the Gospel and the holy Sacraments of the Church, that were bestowed upon every Christian at holy baptism. Unused, they are of no profit to you. But used in the right manner they will open your way to freedom and light.
Let us have recourse to humility on all occasions; for the humble lie prone on the ground, and how can a man fall if he lies on the ground? But a man who stands on a height can easily fall.
Acquire humility, which scorches the demons, obedience, which opens the door for the Son of God to enter a man, faith which saves a man, hope which makes him unashamed; and love which lets not a man fall away from God.
Pray firstly to be purified of passions, secondly to be freed from ignorance and forgetfulness, and thirdly to be delivered from all temptation and forsaking.
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.
Faith and love which are gifts of the Holy Spirit are such great and powerful means that a person who has them can easily, and with joy and consolation, go the way Jesus Christ went. Besides this, the Holy Spirit gives man the power to resist the delusions of the world so that although he makes use of earthly good, yet he uses them as a temporary visitor, without attaching his heart to them. But a man who has not got the Holy Spirit, despite all his learning and prudence, is always more or less a slave and worshipper of the world.
My brother, the passions are afflictions; and so the Lord does not excommunicate us because of them, but He says: 'Call upon me in the time of affliction; and I will deliver thee, and thou shalt glorify me'. Therefore, when beset by any kind of passion, there is nothing more useful than to call upon the Name of God. All we can do, weak as we are, is to flee for refuge to the Name of Jesus. For the passions, being demons, retreat if this Name is invoked.