[3:12] 1 sn Since the author states that Cain…was of the evil one (ἐκ τοῦ πονηροῦ, ek tou ponhrou), in the immediate context this imagery serves as an illustration of 3:8a: The person who practices sin is of the devil (ἐκ τοῦ διαβόλου, ek tou diabolou). This is similar to John 8:44, where Jesus told his opponents “you people are from your father the devil…[who] was a murderer from the beginning.” In both Jewish and early Christian writings Cain is a model for those who deliberately disbelieve; Testament of Benjamin 7:5 looks forward to the punishment of those who “are like Cain in the envy and hatred of brothers.” It is not difficult to see why the author of 1 John used Cain here as a model for the opponents in light of their failure to “love the brothers” (see 1 John 3:17).
[3:12] 2 tn For the Greek verb σφάζω (sfazw) L&N 20.72 states, “to slaughter, either animals or persons; in contexts referring to persons, the implication is of violence and mercilessness – ‘to slaughter, to kill.’” As a reflection of this nuance, the translation “brutally murdered” has been used.
[3:13] 3 tn Grk “brothers,” but the Greek word may be used for “brothers and sisters” or “fellow Christians” as here (cf. BDAG 18 s.v. ἀδελφός 1, where considerable nonbiblical evidence for the plural ἀδελφοί [adelfoi] meaning “brothers and sisters” is cited). Since the author is addressing his readers directly at this point, “brothers and sisters” (suggesting a degree of familial endearment) has been employed in the translation at this point, while elsewhere the less direct “fellow Christians” has been used (cf. v. 14).
[3:13] 4 sn Cf. John 15:18, where this phrase also occurs.
