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 passion of self-esteem is a three-pronged barb heated and forged by the demons out of vanity, presumption and arrogance. Yet those who dwell under the protection of the God of heaven (cf. Ps. 91.1) detect it easily and shatter its prongs, for through their humility they rise above such vices and find repose in the tree of life.
Those who have sinned must not despair. Let that never be. For we are condemned not for the multitude of evils, but because we do not want to repent...
If you want to cure your soul, you need four things. The first is to forgive your enemies. The second is to confess thoroughly. The third is to blame yourself. The fourth is to resolve to sin no more. If we wish to be saved, we must always blame ourselves and not attribute our wrong acts to others. And God, Who is most compassionate, will forgive us.
If we want to do something but cannot, then before God, Who knows our hearts, it is as if we have done it. This is true whether the intended action is good or bad.
The abstinent withdraws from gluttony, the uncovetous from covetousness, the silent from wordiness, the pure from attachment to sensory pleasures, the chaste from fornication, he who is content with what he has from love of money, the meek from agitation (anger), the humble from vanity, the obedient from objection, he who is honest with himself from hypocrisy; equally, he who prays withdraws from despair, the willing pauper from acquisitiveness, he who professes his faith from denying it, the martyr from idolatry – so you see that each virtue, performed even unto death, is nothing but withdrawal from sin; and withdrawal from sin is a natural action, not an action which could be rewarded by the kingdom.
When the first order of angels fell from the angelic glory and became demons, the other nine orders humbled themselves and worshipped the All-holy Trinity, and remained in their place and rejoice forever. We, too, my brethren, must reflect what an evil thing pride is - that it cast down the devil from angelic glory and he will always burn in Hell - and that humility kept the angels in Heaven, and they rejoice perpetually in the glory of the Holy Trinity. Let us then, my brethren, avoid pride, because it is the first daughter of the devil, is a path that leads to Hell; and let us have humility, because it is angelic—it is a path that leads to Paradise.
Praise God continually with spiritual hymns and always remain in meditation and in this way you will be able to bear the burden of the temptations that come upon you. A traveler who is carrying a heavy load pauses from time to time and draws in deep breaths; it makes the journey easier and the burden lighter.
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.