Do not be like Cain, who belonged to the evil one and murdered his brother. And why did Cain slay him? Because his own deeds were evil, while those of his brother were righteous.
Textus Receptus (TR) - 1 John 3:12 >οὐ καθὼς Κάϊν ἐκ τοῦ πονηροῦ ἦν, καὶ ἔσφαξε τὸν ἀδελφὸν αὐτοῦ. Καὶ χάριν τίνος ἔσφαξεν αὐτόν; Ὅτι τὰ ἔργα αὐτοῦ πονηρὰ ἦν, τὰ δὲ τοῦ ἀδελφοῦ αὐτοῦ δίκαια.