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.
Faith is an eye that enlightens every conscience, and imparts understanding; for the Prophet saith, And if ye believe not, ye shall not understand (Is. vii, 9).
He shall be known by his crimes of inhumanity and lawlessness, so as to outdo all unrighteous and ungodly men who have gone before him; displaying against all men, but especially against us Christians, a spirit murderous and most cruel, merciless and crafty.
Oftentimes a man for Christ's sake has been outraged and dishonored unjustly; martyrdom is at hand; tortures on every side, and fire, and sword, and savage beasts, and the pit. But the Holy Spirit softly whispers to him, 'Wait on the Lord, O man; what is now befalling you is a small matter, the reward will be great. Suffer a little while, and you shall be with angels forever. 'The sufferings of this present time are not worthy to be compared with the glory which shall be revealed in us' (Rom. 8:18).' He portrays to the man the kingdom of heaven; He gives him a glimpse of the paradise of delight; and the martyrs, whose bodily faces are of necessity turned to their judges, but who in spirit are already in Paradise, despise those hardships which are seen.
Self-accusation before God is something that is very necessary for us; and humility of heart is extremely advantageous in our lives, above all at the time of prayer. For prayer requires great attention and needs a proper awareness, otherwise it will turn out to be unacceptable and rejected, and `it will be turned back empty' to our bosom.
For God seeks nothing else from us, save a good purpose. Say not, How are my sins blotted out? I tell thee, By willing, by believing. What can be shorter than this? But if, while thy lips declare thee willing, thy heart be silent, He knoweth the heart, who judgeth thee. Cease from this day from every evil deed. Let not thy tongue speak unseemly words, let thine eye abstain from sin, and from roving after things unprofitable.
Though remission of sins is given equally to all, the communion of the Holy Spirit is bestowed in proportion to each man's faith. If you have labored little, you receive little; but if you have wrought much, the reward is great. You are running for yourself, see to your own interest.
Christ told His friends, that is, His disciples, to beware of the leaven of the Pharisees and scribes, meaning by leaven their false pretence. For hypocrisy is a thing hateful to God, and abominated by man, bringing no reward, and utterly useless for the salvation of the soul, or rather the cause of its perdition. Though sometimes it may escape detection for a little, yet before long it is sure to be laid bare and bring disgrace upon them, like ill-featured women, when they are stripped of that external embellishment which they had produced by artificial means. Hypocrisy, therefore, is a thing foreign to the character of the saints. That it is impossible for those things that are done and said by us to escape the eye of the Deity, He showed by saying: “There is nothing covered that shall not be revealed; neither hid that shall not be known.” For all our words and deeds shall be revealed at the day of judgment.
The way of Godliness consists of these two things: True (pious) doctrines and good works. Without good works, true faith is not acceptable to God, likewise, good works are not acceptable to Him in the absence of True Faith (pious dogma).
The view we take of our Savior's dispensation is the view of the holy fathers who preceded us. By reading their works we equip our own mind to follow them and to introduce no innovation into Orthodoxy.