The second command, to love your neighbor, was in the eyes of the elder the touchstone which allows the testing of the righteousness of our path towards God; and also in order to distinguish between good and evil, the safe criterion is not as much the aim we have in view, no matter how holy and sublime it may seem, as the means chosen for reaching that aim.
Only God is absolute. The evil is not a reality which has its own being, but it is an opposition of the free creature against the One Who is the proper Being, God. Therefore it can`t be absolute and for this reason the evil in pure state doesn`t exist and can`t exist. Any evil committed by the free creatures imperiously leads to a parasite life on the `body` of good; he must find a justification, to present itself hidden under the appearance of good and very often under the appearance of the absolute good. The evil always appears in an unavoidable way mixed with an element from a formally positive search and it seduces the man by this characteristic. The evil tries to present to the man its positive aspect as such an important aim that for reaching it any means are allowed.
In his earthly life the man can`t reach the absolute Good; in all human deeds there is a certain degree of imperfection. The presence of imperfection in the human good on one side and on the other side the unavoidable presence of a good pretext in the evil make it extremely hard the distinction between good and evil.
The elder considered that the evil always acts by cunning, hiding itself under the appearance of good, while good doesn`t need evil to fulfill itself; that is why where evil means are used – malice, lie, violence – it begins a territory which is strange to the Spirit of Christ. Good can`t be reached by evil means and the aim doesn`t justify the means. A good acquired by evil means is not a good. This is the teaching the Apostles and the Holy Fathers left us. If not rarely good triumphs and by its presence corrects the evil, it would be wrong to think that good it would be the result of evil. This thing is impossible. But wherever the power of God intervenes, it heals everything, as God is fullness of life and creates life out of nothing.
Excerpt from The life and teaching of the elder Silouan the Athonite, written by his disciple, archimandrite Sofrony, Deisis Publishing.