13 For I am a man of the threshing-floor of Christ: if a bad man, then part of the chaff; if good, then of the grain. The winnowing-fan of this threshing-floor is not the tongue of Petilianus; and hereby, whatever evil he may have uttered, even with truth, against the chaff of this threshing-floor, this in no way prejudices its grain. But whereinsoever he has cast any revilings or calumnies against the grain itself, its faith is tried on earth, and its reward increased in the heavens.
For where men are holy servants of the Lord, and are fighting with holiness for God, not against Petilianus, or any flesh and blood like him, but against principalities and powers, and the rulers of the darkness of this world, such as are all enemies of the truth, to whom I would that we could say, "You were sometime darkness, but now are you light in the Lord," — where the servants of God, I say, are waging such a war as this, then all the calumnious revilings that are uttered by their enemies, which cause an evil report among the malicious and those that are rash in believing, are weapons on the left hand: it is with such as these that even the devil is defeated.
For when we are tried by good report, whether we resist the exaltation of ourselves to pride, and are tried by evil report, whether we love even those very enemies by whom it is invented against us, then we overcome the devil by the armor of righteousness on the right hand and on the left. For when the apostle had used the expression, "By the armor of righteousness on the right hand and on the left," he at once goes on to say, as if in explanation of the terms, "By honor and dishonor, by evil report and good report," and so forth—reckoning honor and good report among the armor on the right hand, dishonor and evil report among that upon the left.
Source: Answer to Letters of Petilian, Bishop of Cirta (New Advent)