They hate every sin, every impure thing, and everything not pleasing to God. But he says: do not share in them. For one may become guilty of another’s evil by participating in his deeds, even without doing evil oneself.
How? Whenever agreement with the evil deeds of others is somehow manifested. There are many occasions for this. The final limit is this: if you see, hear, or know, and yet keep silent.
The Apostle has this in view and says: do not be silent, but reprove. Does every Christian have to do this? Consider the flow of the Apostle’s speech.
Here it is directed to those who have conquered the passions, to the perfect, who know how to determine exactly what is pleasing to God in each case. Such people know when and how to direct reproving speech so that it benefits others.
Reproof is a knife. One who does not know how to use it may only make wounds that produce worse evil, instead of cutting away a sore or growth for the healing of the sick man.
Blessed Jerome looks at this matter from the same side: “To reprove others is a matter of great importance. Only the one to whom the following rebuke does not apply can do it worthily: ‘Hypocrite, first take the beam out of your own eye, and then you will see to take the speck out of your brother’s eye’ (Lk 6:42).
Thus the prophets, unstained by any impurity of sins and possessing an undefiled conscience, could reprove others who sinned. From this it follows that the one who can reprove is he who is not reproved in himself by his conscience.”
This can apply only to perfect Christians, of whom the Apostle is speaking. Yet everyone can refuse to agree with the one who acts badly, refuse to approve him, and not speak indulgently about evil even in jest.
Even by one’s expression one can say much. The reproof accessible to all is the reproof by the light of deeds. One who withdraws by his action shows that he does not approve what he withdraws from.
For this reason the life of the truly God-fearing is always a reproof of the impious and sinful. One must stand firm in the Christian rules of life and, by shining amid the surrounding darkness of deeds, reprove them.
Photius says in Oecumenius: “Reprove, he says, by the manner of your life. I do not say: reprove them by listing their deeds and rebuking them for them.
For I know that zealots of purity consider even the remembrance of them a defilement. Meanwhile they will be reproved no less when your deeds shine with virtues.
Their deeds will be reproved, uncovered, and revealed by the light of your life. Once revealed, they will be illumined and changed and transformed for the better.
The revelation of the shame of their deeds by your life will bring them to awareness and self-condemnation. This is the beginning of conversion and correction.”
Thus the bright life of Christians silently brings the negligent to the very point to which the reproving word of the perfect is appointed to bring them.