One should never believe in oneself or trust oneself in anything
“Not to rely on oneself is so necessary in our struggle, my beloved brother, that without this, be assured, not only will you fail to gain the desired victory, but you will be unable to resist the smallest attack of the enemy. Engrave this deeply in your mind and heart.
Since the time of the transgression of our forefather, despite the weakening of our spiritual and moral powers, we are wont to think very highly of ourselves. Although our daily experience very effectively proves to us the falseness of this opinion of ourselves, in our incomprehensible self-deception we do not cease to believe that we are something, and something not unimportant. Yet this spiritual disease of ours, so hard to perceive and acknowledge, is more abhorrent to God than all else in us, as being the first offspring of our self-hood and self-love, and the source, root and cause of all passions and of all our downfalls and wrong-doing. It closes the very door of our mind or spirit, through which alone Divine grace can enter, and gives this grace no way to come and dwell in a man. And so it withdraws from him. For how can grace, which comes to help and enlighten us, enter that man, who thinks of himself that he is something great, that he himself knows everything and needs no outside help?—May God preserve us from this disease and passion of Lucifer!—God severely reprimands those who are stricken with this passion of vainglory and self-esteem, saving through the prophet: ‘Woe unto them that are wise in their own eyes, and prudent in their own sight’ (Isaiah v. 21). And the Apostle tells us: ‘Be not wise in your own conceits’ (Rom. xii. 16).
While God abhors this evil conceit in us, there is nothing He loves and desires to see in us more than a sincere consciousness of our nothingness and a firm and deep-felt conviction that any good we may have in our nature and our life comes from Him alone, since He is the source of all good, and that nothing truly good can ever come from ourselves, whether a good thought or a good action. Therefore He takes care to plant this heavenly seed in the hearts of His beloved friends, urging them not to value themselves and not to rely on themselves. Sometimes He does this through the action of grace and inner illumination, or sometimes through external blows and tribulations, sometimes through unexpected and almost unconquerable temptations, and sometimes by other means, not always comprehensible to us. Yet, although expecting no good from ourselves and not relying on ourselves is the work of God in us, we on our side must make every effort to acquire this disposition, doing all we can, all within our power. And so, my brother, I offer you here four activities by means of which, with God’s help, you may end by acquiring disbelief in yourself, and learn never to rely on yourself in anything.
(a) realize your nothingness and constantly keep in your mind the fact that by yourself you can do nothing good which is worthy of the kingdom of heaven. Listen to the words of the wise fathers: Peter of Damascus assures us that ‘nothing is better than to realize one’s weakness and ignorance, and nothing is worse than not to be aware of them’ (Philokalia). St. Maximus the Confessor teaches: ‘The foundation of every virtue is the realization of human weakness’ (Philokalia). St. John Chrysostom says: ‘He alone knows himself in the best way possible who thinks of himself as being nothing.’
(b) Ask for God’s help in this with warm and humble prayers, for this is His gift. And if you wish to receive it, you must first implant in yourself the conviction that not only have you no such consciousness of yourself, but that you cannot acquire it by your own efforts; then standing daringly before the Almighty God, in firm belief that in His great loving kindness He will grant you this knowledge of yourself when and how He Himself knows, do not let the slightest doubt creep in that you will actually receive it (that you are worthy of it).
(c) Accustom yourself to be wary and to fear your innumerable enemies whom you cannot resist even for a short time. Fear their long experience in fighting us, their cunning and ambushes, their power to assume the guise of angels of light, their countless wiles and nets, which they secretly spread on the path of your life of virtues.
(d) If you fall into some transgression, quickly turn to the realization of your weakness and be aware of it. For God allows you to fall for the very purpose of making you more aware of your weakness, so that you may thus not only yourself learn to despise yourself, but because of your great weakness may wish to be despised also by others. Know that without such desire it is impossible for this beneficent self-disbelief to be born and take root in you. This is the foundation and beginning of true humility, since it is based on realization, by experience, of your impotence and unreliability.
From this, each of us sees how necessary it is for a man, who desires to participate in heavenly light, to know himself, and how God’s mercy usually leads the proud and self-reliant to this knowledge through their downfalls, justly allowing them to fall into the very sin from which they think they are strong enough to protect themselves, so as to make them see their weakness and prevent them from relying foolhardily on themselves either in this or in anything else.
This method, although very effective, is also not without danger, and, God does not always use it, but only when all the other means we have mentioned, which are easier and more natural, fail to lead a man to self-knowledge. Only then does He finally let a man fall into sin, great or small, in accordance with the degree of his pride, conceit and self-reliance. So that where conceit and self-reliance are absent, instructive failures do not occur. Therefore, if you happen to fall, run quickly in your thought to humble self-knowledge and a low opinion and sense of yourself and implore God by persistent prayer to give you true light, so as to realize your nothingness and confirm your heart in disbelief in yourself, lest you again fall into the same or even worse and more destructive sin.
I must add that not only when a man falls into some sin, but also when he is afflicted by some ill-fortune, tribulation or sorrow, and especially a grievous and long-drawn bodily sickness, he must understand that he suffers this in order to acquire self-knowledge, namely the knowledge of his weakness—and to become humble. With this purpose and to this end God allows us to be assailed by all kinds of temptations from the devil, from men and from our own corrupted nature. St. Paul saw this purpose in the temptations he suffered in Asia, when he said: ‘But we had the sentence of death in ourselves, that we should not trust in ourselves, but in God which raiseth dead’ (II Cor. i. 9).
And I shall add another thing: if a man wants to realize his weakness from the actual experience of his life, let him, I do not say for many days but even for one day, observe his thoughts, words and actions—what he thought, what he said, what he did. He will undoubtedly find that the greater part of his thoughts, words and actions were sinful, wrong, foolish and bad. This experiment will make him understand in practice how inharmonious and weak he is in himself. And if he sincerely wishes himself well, this understanding will make him feel how foolish it is to expect anything good from himself or to rely on himself alone.”
Source: St. Theophan the Recluse, Unseen Warfare, Chapter 2, pp. 7-8