"... Cain is portrayed in 1 John as the original man-hater and man-murderer, and this interpretation of Cain’s story goes beyond what is reported in Genesis 4:4-9: Cain’s hatred in 1 John is the “original hatred” that comes from darkness. A reasonable conclusion, therefore, is that the author’s use in 1 John 3:12 derives from the tradition available to him, in which Cain’s action in killing his brother is intensified from an act of simple killing borne of brotherly jealousy, as portrayed in the Torah, to a manifestation of primaeval evil, done by a person who himself stands as the all-time personification of evil itself, such as we find in Philo and Josephus. Further, we have noticed that even in the LXX, Genesis 4:8 uses the word which simply means “kill”, to translate the Hebrew ַ וַ יּה גְר הוּ, “and he killed him”, which has a similar meaning, even if the Greek is slightly intensified compared to the Hebrew ... To say, as 1 John 3:12 does, that Cain ἔσφαξεν τὸν ἀδελφὸν αὐτοῦ, “slaughtered his brother, is a great step-up from the simple LXX statement ..."