St. Ignatius (Brianchaninov). "On Prelest". On Guarding Oneself from the Good That Belongs to Fallen Human Nature.
Has some good thought come to you? Stop: whatever you do, do not rush to implement it or carry it out overhastily, without thinking. Have you felt some good impulse or inclination in your heart? Stop; do not dare to be drawn by it. Check it with the Gospel. See whether your good thought and your heart's good impulse tally with the Lord's holy teaching. You will soon see that there is no agreement whatever between the good of the Gospel and the good of fallen human nature.
The good of our fallen nature is mixed with evil, and therefore this good has itself became evil, just as delicious and wholesome food becomes poison when it is mixed with poison. Guard yourself from doing the good of fallen nature. By doing this good, you develop your own fall, you develop within you self-opinion and pride, and you will attain the closest conformity with demons. On the other hand, by doing the good of the Gospel as a true and faithful disciple of the God-Man, you will become like the God-Man. “He that loveth his life shall lose it; and he that hateth his life in this world shall keep it unto life eternal” (Joh. 12:25).
“Whosoever will come after me, let him deny himself, and take up his cross, and follow me. For whosoever will save his life shall lose it; but whosoever shall lose his life for my sake and the gospel's, the same shall save it.” (Mk 8:34-35)
The Lord orders the complete renunciation of fallen nature, and hatred for its motives and impulses, not only for those which are clearly evil, bur for all without exception, even the apparently good. It is a great disaster to follow the righteousness of fallen nature. This implies and involves rejection of the Gospel, rejection of the Redeemer, rejection of salvation. “If any man come to me, and hate not…. yea, and his own life also, he cannot be my disciple” (Luk.24:26), said the Lord.
Explaining the above words of our Lord, Barsanuphius the Great says, “How does a man renounce himself? Simply by forsaken his natural desires and following the Lord. That is why the Lord speaks here strictly of what is natural, and not of what is unnatural. For if anyone forsakes only what is unnatural, he has not yet forsaken anything of his own for God's sake, because what is unnatural does not properly belong to him. But whoever has forsaken what is natural, always says with the Apostle Peter, ‘Behold, we have forsaken all, and followed Thee; what shall we have therefore?’(Mat.19:27-29) And he hears the blessed voice of the Lord, and by His promise is assured of the inheritance and possession of eternal life (Mat. 19:27,29).
What did Peter renounce and what was his boast, as he was not rich; surely he renounced his own natural desires? For unless a man dies to the flesh and lives in the spirit, his soul cannot rise. Just as in a corpse there are no natural desires whatever, so too there are none in a person who is spiritually dead to the flesh. If you have died to the flesh, how can natural desires live in you? But if you have not attained this measure of spirituality and are mentally still in your infancy, humble yourself before a teacher, that he may ‘chasten you with mercy’ (Ps 140/141:5), and ‘do nothing without counsel’ (Sirach 32:21) even though it may seem to you apparently good. For the light of demons eventually turns to darkness (Answer 59).
Exactly the same must be said also about the light of fallen human nature. Following this light and its development within oneself produces a total inner darkness and completely estranges the soul from Christ. A stranger to Christ is a stranger to God. “Whosoever denieth the Son, the same hath not the Father” (1 John. 2:23) – he is godless.
In our time the majority of people, proud of their progress and claiming to be Christions who do a lot of good, have been striving for the perfection of the righteousness of the Gospel. Let this majority listen to what the Lord says: ‘This people draweth nigh unto me with their mouth, and honoureth me with their lips; but their heart is far from me. But in vain they do worship me, teaching for doctrines the commandments of men’ (Mat 15:8-9).
The man who practices human righteousness is full of self-opinion, arrogance, self-deception. He preaches and blows his own trumpet about his good deeds without paying the least attention to what our Lord forbids (Mat.6:1-18). He repays with hatred and revenge those who dare to open their mouths for the most reasonable and well-meaning contradiction of his righteousness. He considers himself deserving and more than deserving of both earthly and heavenly rewards.
On the other hand, one who practices the commandments of the Gospel is always immersed in humility. Comparing the loftiness and purity of the holy commandments with his own fulfillment of them, he constantly admits that his efforts are extremely unsatisfactory and unworthy of God. He sees himself meriting temporal and eternal punishments for his sins, for his unbroken fellowship with Satan, for the fall that is common to all men, for his own continuance in a fallen state, and finally for his insufficient and frequently fickle fulfillment of the commandments. Whenever trouble or suffering comes his way by the ordering of divine providence, he submissively bows his head, knowing that by means of suffering God trains and educates His servants during their earthly pilgrimage. He is kind and merciful to his enemies and prays for them as brothers who have been lured away by demons, as members of one body who are spiritually sick, as his benefactors, and as instruments of the providence of God.
 Numbering of psalms in Septuagint and King James Bible accordingly.