Do not imitate the evil: do not imitate the proud, impious, and inhospitable Diotrephes, even though he does occupy the chief place in the Church, but rather imitate the humble, pious, and hospitable Demetrius, of whom in ver12.
He who does good is of God, &c. This is especially applicable to the good of kindness and beneficence. And this is the chief meaning of the Greek Î±Ì‰Î³Î±Î¸Î¿Ï€Î¿Î¹ÎµÎ¹ÌƒÎ½, which is to benefit, or do a kindness to any one. For S. John is here treating of kindness and hospitality. For this he praises Caius, whilst he condemns the unkindness of Diotrephes. He is alluding to what he says in his first Epist. iii6. The meaning Isaiah , He who does to them that need—as, for instance, by receiving guests and pilgrims, as thou doest, 0 Caius—is of God. He knows, loves, and worships Him. But he who does ill to his neighbour, as Diotrephes does, is not of God: he neither sees, nor hath seen Him: that Isaiah , practically, he does not know God, because he does not love, imitate, or worship Him. Although indeed every virtue is of God, the words especially apply to charity and beneficence. For it is an attribute of God that He communicates Himself and His good things, and doeth good.
The reason Isaiah , because it is a property of God so to abound in all good that He overflows, and pours out his goodness by bestowing it upon others. He therefore that shows kindness is a child and an imitator of the good and kind God.
He that doeth evil hath nor seen God. The direct antithesis would have been, is not of God, but S. John amplifies, saying, so much is he not of God, that he does not see, i.e. practically know God. He who is unkind, and does evil to his neighbour, does not truly see, i.e. know God practically, because he does not acknowledge God"s infinite and unceasing kindnesses to himself, so as to show himself grateful for them by showing kindness to others for God"s sake.
S. Dionysius, writing to the same Caius, the Therapeut, i.e. the Seer and Contemplative, which is the reason why the Apostle speaks of seeing God, alludes to these words of the Apostle. And he explains in what way good and perfect men, especially Therapeuts like Caius, see God: "If there be any one who when he has seen God has understood what he has seen, he hath not seen Him, but something of Him which is and is known. But He Himself being placed on high above all understanding and all being, far surpasses all understanding." For God being in Himself invisible transcends all things, and inhabits the unapproachable light, which is to us impenetrable darkness, as the same Dionysius teaches elsewhere. He proves the same thing by the example of S. Paul, who, although he was rapt up to God, nevertheless declares that God surpasses all understanding and knowledge. Hence also our John the Evangelist says in his Gospel (i. i8), "No man hath seen God at any time," namely, by any clear vision. For men have seen Him imperfectly by faith, according to the words, "now we see through a mirror in an enigma." ( 1 Corinthians 13:12. Vulg.)