Augustine of Hippo — as excerpted in the Catena Aurea on John 15:17-21

“(Tract. lxxxviii. 2) All these things, viz. what He had mentioned, that the world would hate them, persecute them, despise their word. For My Name’s sake, i. e. in you they will hate Me, in you persecute Me, your word they will not keep, because it is mine. They who do these things for His name’s sake are as miserable, as they who suffer them are blessed: except when they do them to the wicked as well; for then both they who do, and they who suffer, are miserable. But how do they do all these things for His name’s sake, when they do nothing for Christ’s name’s sake, i. e. for justice sake? We shall do away with this difficulty, if we take the words as applying to the righteous; as if it were, All these things will ye suffer from them, for My name’s sake. If, for My name’s sake, mean this, i. e. My name which they hate in you, justice which they hate in you; of the good, when they persecute the wicked, it may be said in the same way, that they do so both for righteousness’ sake, which they love, which love is their motive in persecuting, and for unrighteousness’ sake, the unrighteousness of the wicked, which they hate. Because they know not Him that sent Me, i. e. know not according to that knowledge of which it is said, To know Thee is perfect righteousness. (Wisd. 15:3)”