In Christ's Sermon on the Mount there are well-known words: "The lamp of the body is the eye. Therefore, if thy eye be pure, thy whole body shall be light; but if thy eye be evil, thy whole body shall be dark..." The Holy Fathers say that in these words the "eye" should be understood as the human mind. Just as for the body, for the material side of human nature, the eye is the main means of orientation during movement and any of its activities, so for the soul such a means is the mind. The body looks and sees with the eyes, and the soul sees with the mind. There is external, bodily sight, and there is internal vision, vision with the mind, speculation. If a person has healthy eyes, then he clearly distinguishes all objects of the material world and therefore can easily move, work and do any business. And if the eyes are unhealthy, then a person does not distinguish objects well, poorly understands the road and cannot or with great difficulty can do anything in our world.

All that has been said is true of the human mind as well. The mind is the eye of the soul, it must see reality accurately and correctly show it to a person. The mind's ability to perceive reality depends on its way of thinking—on the ideas, principles, and attitudes that it has internalized. If these thoughts, ideas and attitudes are true and correct, if they are drawn from the Holy Scriptures, from the Tradition of the Church, from the works of the Holy Fathers, then the human mind will be like a healthy and sharp eye that clearly sees the path it is following, sees all the obstacles and unmistakably distinguishes good from evil and truth from error. If the mind has been poisoned by prejudices, darkened by false thoughts and ideals, then such a mind loses the ability to see clearly and sharply and can no longer orient itself correctly. He loses his way and begins to wander through the deserts, wilderness, and swamps, being in danger of drowning and perishing, which, of course, is aided by the enemy of our salvation, the devil, with all his might. "False thoughts," says St. Ignatius Brianchaninov, "are always present and assisted by the dark and evil spirit of deception. The father of lies is the devil, so says the Gospel, lying is a devilish property. He who assimilated false thoughts to himself assimilated to himself the qualities of the devil, entered into kinship with the rejected angels, made for himself union with God unkind, unnatural. He who is a stranger to God is a stranger to salvation and spiritual life."

And again the words of St. Ignatius: "The enemy of human salvation tries to lure our thoughts out of the abode of truth with various phantoms of truth. He knows the power of this network. This net seems insignificant to the untrained eye; the mind is attracted to it by curiosity, by the pompous, holy name with which destruction is usually covered. Thus the gullible nightingale, a particularly curious bird, is lured by the food scattered under the net, and falls forever into dull captivity. A false thought is pernicious: it introduces delusion and self-deception into the soul, and makes it a prisoner of the world's ruler. The truth will make you free, said the Saviour; it is obvious that lies deprive of freedom, subordinate the power of the prince of this world."

Knowing all this well, the enemy of our salvation always tries to implant in the minds of people the false and pernicious ideas and thoughts he desires, in order to subordinate people to his power and destroy them. The enemy acts in this mental battle in different ways. Sometimes he brings and puts all kinds of thoughts directly into a person's head. The devil received the right to put any thoughts into the human mind from the time of the fall of Adam. St. John of Kronstadt said that there is no such vile, blasphemous, blasphemous, deceitful and pernicious thought that the devil could not put into the head of a person. We are not able to forbid the enemy to put these thoughts into our minds, we are not given the power to do so. But we can (and we have the power to do so) treat them rightly—that is, not to accept these thoughts, to despise them, not to assimilate them, and to consider them alien to us. This is the so-called mental warfare that all Christians, both laymen and especially monks, are called to conduct. In monks, such warfare can reach an extraordinary degree of intensity and sharpness.

The second means used by the devil to sow the thoughts and ideas he needs in people's minds are the sources of information that man uses in our world. This includes books, films, newspapers, magazines, advertising, the Internet, radio, television. Through all this, people get access to a vast sea of information. In this sea there is everything, both good and bad, good and evil, true and false. Alas, very often people draw from it precisely the bad, false and disastrous – thoughts and ideas that are hostile to Christianity, confuse a person and lead him far away from the path of salvation.

Чего только не насевают в наши головы с помощью средств массовой информации! Нам, например, внушают оттуда, что деньги, успех, власть, слава и удовольствия — это главное в жизни и что надо добиваться этого любой ценой; нам внушают, что «свободная любовь» выше супружеской верности и не подлежит лицемерному осуждению; нам внушают, что все религии равны и одинаково учат добру; что целомудрие вредно для здоровья, а распущенность и извращения, напротив, полезны и не являются грехом; что христианство устарело, а Церковь пригодна только для отсталых людей, — вот лишь немногие, самые общие штампы и установки, которые в избытке можно почерпнуть в мирском море информации. И не нужно думать, что эти мысли и идеи безобидны, что они не оказывают на нас особого влияния, — нет, все идеи и мысли, которые ум получает извне, никуда не деваются, они живут в таинственных глубинах нашей памяти и потом, иногда по прошествии долгого времени, вдруг всплывают и могут оказать определяющее влияние на поведение человека в той или иной жизненной ситуации, стать причиной того или иного выбора.

Вот, например, человек совершил преступление, причем такой человек, от которого никто не ожидал ничего подобного, и все удивляются: откуда? почему? как он мог? А мог он потому, что в решающую минуту выбора у него сработала установка, штамп, идея, почерпнутая им когда-то из книжки или фильма, где красивый герой бросил эффектную фразу о том, что ради больших денег можно один раз пойти и на сделку со своей совестью.