Καὶ πάλιν Ἰωάννης ὁ θεολόγος λέγει· Ὁ μισῶν τὸν ἀδελφὸν αὑτοῦ, ἐν τῇ σκοτίᾳ ἐστι, καὶ ἐν τῷ σκότει περιπατεῖ, καὶ οὐκ οἶδε ποῦ ὑπάγει, ὅτι ἡ σκοτία ἐτύφλωσε τοὺς ὀφθαλμοὺς αὐτοῦ. Ἐὰν δὲ εἴπῃς, ὅτι Κἂν τὸν ἀδελφόν μου οὐκ ἀγαπῶ, ἀλλὰ τὸν Θεὸν ἀγαπῶ, ἐλέγχει σε Ἰωάννης λέγων· Ἐάν τις εἴπῃ, Τὸν Θεὸν ἀγαπῶ, καὶ τὸν ἀδελφὸν αὑτοῦ μισεῖ, ψεύστης ἐστίν. Ὁ γὰρ μὴ ἀγαπῶν τὸν ἀδελφὸν αὑτοῦ, ὃν ἑώρακε, τὸν Θεὸν, ὃν οὐχ ἑώρακε, πῶς δύναται ἀγαπᾷν; Ὁ οὖν ἔχων μετὰ πάντων τῶν ἀδελφῶν ἀγάπην, ὁ μὴ ἔχων ἔχθραν κατά τινος, ὁ πληρῶν τὸν λόγον τοῦ Ἀποστόλου, Ὁ ἥλιος μὴ ἐπιδυέτω ἐπὶ τὸν παροργισμὸν ὑμῶν, οὗτος ἀγαπᾷ τὸν Θεὸν, οὗτος μαθητὴς αὐτοῦ ἐστι, τοῦ εἰπόντος, ὅτι Ἐν τούτῳ γνώσονται πάντες ὅτι ἐμοῦ μαθηταί ἐστε, ἐὰν ἀγάπην ἔχητε μετ᾽ ἀλλήλων. Φανερὸν οὖν ἐστιν, ὅτι οἱ τοῦ Χριστοῦ μαθηταὶ ἐκεῖθεν γνωρίζονται ἐκ τῆς ἀληθινῆς ἀγάπης. Ὁ δὲ ἔχων μῖσος κατὰ τοῦ ἀδελφοῦ αὐτοῦ, κἂν δοκῇ ἀγαπᾷν τὸν Χριστὸν, ψεύστης ἐστὶ καὶ φρεναπατᾷ ἑαυτόν. Λέγει γὰρ ὁ ἀπόστολος Ἰωάννης, ὅτι Ταύτην ἐντολὴν ἔχομεν παρ᾽ αὐτοῦ, ἵνα ὁ ἀγαπῶν τὸν Θεὸν, ἀγαπᾷ καὶ τὸν ἀδελφὸν αὑτοῦ· καὶ πάλιν ὁ Κύριος, Ἀγαπήσεις Κύριον τὸν Θεόν σου ἐξ ὅλης τῆς καρδίας σου, καὶ τὸν πλησίον σου ὡς ἑαυτόν· καὶ ἐπήγαγε, θέλων δεῖξαι τὴν δύναμιν τῆς ἀγάπης, λέγων· Ἐν ταύταις ταῖς δυσὶν ἐντολαῖς ὅλος ὁ νόμος καὶ οἱ προφῆται κρέμανται.