The concept of prelest is very important in Orthodox spirituality and ascetics. It is one of the main dangers for a Christian (especially monastic) starting to pray with the [[Jesus Prayer]].<ref name="piligr">[http://www.pravmir.com/the-way-of-a-pilgrim-and-bishop-ignatius-brianchaninov%E2%80%99s-teaching-on-prayer-2/ Interview with prof. A.I. Osipov. "The Way of a Pilgrim" and Bishop Ignatius (Brianchaninov’s) Teaching on Prayer".]</ref>

Professor N.E. Pestov in his book<ref>{{Ru icon}}[http://azbyka.ru/tserkov/duhovnaya_zhizn/osnovy/pestov_praktika_pravoslavnogo_blagochestiya_27-all.shtml N.E. Pestov. Practice of Orthodox Devoutness.]</ref> writes that in general, the safest spiritual path in relation to prelest is to live in obedience to an experienced and holy elder, or at least to live on the advice of others. The fastest way to fall into prelest is the opposite - to trust own thoughts and not to listen to any advice.

Also Elder [[Daniel Katounakiotis]] writes about several such cases of long condition of prelest accompanied by visions. He writes in a letter about one hierodeacon by the name of Ierotheos who had a lot of visions. Even though he confessed everything, nobody of the confessors understood that this was a delusion. Then elder [[Sabbas the Father Confessor of Mount Athos‎|Sabbas]] advised him how to find out the truth. After that the delusion was revealed. But in spite of the fact that the visions ceased after repeated exorcism, the injury to the soul of Ierotheos remained very serious and later he broke all monastic vows. Another case of prelest happened to a lay man Nicolaus. He was also subjected to a long and strong action of demons. Even though elder Daniel convinced Nicolaus that all his visions were false, the traces of delusion were seen to the end of his life.<ref>[http://oprelesti.ru/index.php/kinds-of-spiritual-delusion/134-false-visions/653-elder-daniel-about-the-visions Answer of monk Daniel to Marcian, a monk of the Iveron skete, on rejection of dreams]</ref>

===Self-conceit===

Apostle James warns against unauthorized teaching in his Epistle: "My brethren, be not many masters, knowing that we shall receive the greater condemnation" (James 3:1). If the desire of teaching in the particular person originates from the passions of vainglory and pride rather than from love and humility, it becomes a kind of prelest, being based on a false idea of personal dignity and ability to teach and that such teaching is pleasing to God. Archbishop [[Averky (Taushev) of Syracuse|Averky (Taushev)]] in his analysis of James 3:1 says that one should start teaching with the great caution and distrust to oneself.<ref>{{Ru icon}}[http://azbyka.ru/hristianstvo/bibliya/tolkovanie/averkiy_sobornye_poslaniya_10-all.shtml Archbishop Averky (Taushev). Exegetic analysis of the Epistle of James.]</ref> Such inner determination is opposite to pride and conceited opinion about personal merits. St. [[John Climacus]] also warns about forbidden teaching when he speaks about vainglory: "Ignore him when he tells you to accept the office of bishop or abbot or teacher. It is hard to drive a dog from a butcher's counter."<ref>St. John Climacus. The ladder of Divine Ascent. Step 22.</ref>

* arbitrary teaching and advice without being asked (except for the cases when the person was explicitly appointed to teach without being asked);

* teaching someone who is not interested in the topic or who does not have previous experience and knowledge to understand;

The conceited teacher often does not notice that he does harm to his students because they do not understand, understand incorrectly or even cannot understand at all some subject not having enough experience or knowledge, but the teacher does not cease his teaching. Lord Jesus warns against teaching those who are unprepared and cannot understand: "Give not that which is holy unto the dogs, neither cast ye your pearls before swine, lest they trample them under their feet, and turn again and rend you." (Matthew 7:6). St. [[John Chrysostom]] in the interpretation of these words says that the corruption of life is the reason why the teaching is not understood.<ref>[http://www.ccel.org/ccel/schaff/npnf110.iii.XXIII.html St. John Chrysostom. Homilies on the Gospel of Saint Matthew. VII.]</ref> St. Symeon the New Theologian speaks in a similar way about teaching of something that cannot be understood: "the one who speaks about the ultimate steps of perfection to the novices and especially to the most lazy of them, not only does not help them, but also makes them to go back".<ref>{{Ru icon}}[http://azbyka.ru/otechnik/?Dobrotoljubie/dobrotoljubie_tom_5=2 St. Symeon the New Theologian. Practical and theological chapters. Ch. 160.]</ref> The same idea about teaching of high matters is expressed by [[Apostle Paul]]: "But the natural man receiveth not the things of the Spirit of God: for they are foolishness unto him: neither can he know them, because they are spiritually discerned." (1 Corinthians 2:14)

Regarding arbitrary (i.e. without permission of the bishop) teaching in the church, the rule 64 of the [[Sixth Ecumenical Council]] reads: "That a layman must not publicly make a speech or teach, thus investing himself with the dignity of a teacher, but, instead, must submit to the ordinance handed down by the Lord, and to open his ear wide to them who have received the grace of teaching ability, and to be taught by them the divine facts thoroughly. <...> If anyone be caught disobeying the present Canon, let him be excommunicated for forty days."<ref>[http://www.intratext.com/IXT/ENG0835/__P3S.HTM Canons of the seven [[Ecumenical Councils|ecumenical councils]]. [[Quinisext Council|Quinisext Ecumenical Council]]. Rule 64]</ref> The interpretation of this canon then reads: "But if any layman chance to be experienced in discourse and modest in manner, he is not prohibited from answering and teaching in private those asking questions, as Zonaras states, and ch. 32 of Book VIII of the Apostolic Injunctions declare. For they shall be, it says, all taught of God: in which manner Apollos spoke, and taught the facts about the Lord, and in spite of the fact that he only knew the baptism of the Lord (Acts 28:25), and Aquilas and Priscilla, who taught the same Apollos the way of God more exactly".

''Surrounded by the brothers at the moment of his death, he was as if talking with invisible beings. The brothers asked him, "Father, tell us, with whom are you speaking?" He answered, "With angels who have come to take me; but I am begging them to leave me for a short time, in order to repent." The brothers knew that Sisoes was perfect in the virtues, and protested, "You have no need to repent, Father." Sisoes answered, "Truly, I do not know if I have even begun to repent."''

A.I. Osipov also says<ref name="lec1">{{Ru icon}}[http://alexey-osipov.ru/video/kurs-seminarii-i-akademii-2006-2007/2007-01-22-s5-mistika-i-prelest/ A.I. Osipov. Lecture for the students of the 5th year at Moscow Theological Seminary and Academy, 22.01.2007.]</ref> that there are 3 main manifestations of delusions of Catholic mystics:

Father George Macris also compares the mysticism of St. Seraphim of Sarov and St. Francis of Assisi and analyses in detail different manifestations of their humility. He writes in the conclusion that St. Francis "moved progressively in his life in a growing condition of plani"; "as startling as it may appear to some, he bore many characteristics which are prototypical of Antichrist, who will also be seen as chaste, virtuous, highly moral, full of love and compassion, and who will be regarded as holy (even as a deity) by people who have allowed carnal romanticism to replace the Sacred Tradition of the Holy Church"; "The sad fact is that the attainment of a true spiritual relationship with Christ was never a possibility for Francis, for being outside the Church of Christ, it was impossible that he could have received Divine Grace, or any of the gifts of the Holy Spirit. His gifts were from another spirit".<ref>[http://www.fatheralexander.org/booklets/english/st_francis_st_seraphim.htm George Macris. A Comparison of the Mysticism of Francis of Assisi With That of St. Seraphim of Sarov.]</ref>

Also Prof. A.I. Osipov says that, in his opinion, this is the key to the separation between the Eastern and Western Churches - not filioque or papal supremacy - these are only consequences visible to everyone. The beginning was in the spiritual deviation of the people who turned from the path of fight with passions to the path of false love to God.

St. [[Peter of Mount Athos]] had many false visions trying to scare or delude him. During the first year of solitary life at Mt. Athos, St. Peter suddenly saw a "boy", whom he knew before. They started to speak and the "boy" tried to convince St. Peter to return home. St. Peter replied that he would listen only to the Mother of God since She had commanded him to settle at Mt. Athos. When St. Peter pronounced the name of the Mother of God, the demon disappeared.

When St. [[Gregory the Decapolite]] was living in a cave, he had many demonic assaults. Once the demons appeared as [[Forty Martyrs of Sebaste]] and said that they came to give him the grace and power over demons. But St. Gregory understood their plots and rejected the vision.<ref>{{Ru icon}}[http://ru.wikisource.org/wiki/%D0%96%D0%B8%D1%82%D0%B8%D1%8F_%D1%81%D0%B2%D1%8F%D1%82%D1%8B%D1%85_%28%D0%94%D0%B8%D0%BC%D0%B8%D1%82%D1%80%D0%B8%D0%B9_%D0%A0%D0%BE%D1%81%D1%82%D0%BE%D0%B2%D1%81%D0%BA%D0%B8%D0%B9%29/%D0%9D%D0%BE%D1%8F%D0%B1%D1%80%D1%8C/20 Living of the saints by St. Demetrios of Rostov. November 12.]</ref>