1 tn Grk “the one saying he is in the light and hating his brother.” Here καί (kai) has been translated as “but” because of the contrast present in the two clauses.
2 tn Grk “his brother.” Here the term “brother” means “fellow believer” or “fellow Christian” (cf. BDAG 18 s.v. ἀδελφός 2.a). In the repeated uses of this form of address throughout the letter, it is important to remember that sometimes it refers (1) to genuine Christians (those who have remained faithful to the apostolic eyewitness testimony about who Jesus is, as outlined in the Prologue to the letter, 1:1-4; an example of this usage is 2:10; 3:14, 16), but often it refers (2) to the secessionist opponents whose views the author rejects (examples are found here at 2:9, as well as 2:11; 3:10; 3:15; 3:17; 4:20). Of course, to be technically accurate, in the latter case the reference is really to a “fellow member of the community”; the use of the term “fellow Christian” in the translation no more implies that such an individual is genuinely saved than the literal term “brother” which the author uses for such people. But a translation like “fellow member of the community” or “fellow member of the congregation” is extremely awkward and simply cannot be employed consistently throughout.
3 tn See note on the term “fellow Christian” in 2:9.
4 tn The third person pronoun αὐτῷ (autw) could refer either (1) to the person who loves his brother or (2) to the light itself which has no cause for stumbling “in it.” The following verse (2:11) views darkness as operative within a person, and the analogy with Ps 119:165, which says that the person who loves God’s law does not stumble, expresses a similar concept in relation to an individual. This evidence suggests that the person is the referent here.
5 tn See note on the phrase “fellow Christian” in 2:9.
6 sn Everyone who hates his fellow Christian is a murderer. On one level it is easy to see how the author could say this; the person who hates his brother is one and the same with the person who murders his brother. Behind the usage here, however, is John 8:44, the only other occurrence of the Greek word translated murderer (ἀνθρωποκτόνος, anqrwpoktonos) in the NT, where the devil is described as a “murderer from the beginning.” John 8:44 refers to the devil’s role in bringing death to Adam and Eve, but even more to his involvement (not directly mentioned in the Genesis account, but elaborated in the intertestamental literature, especially the writings of Philo) in Cain’s murder of his brother Abel. This was the first incident of murder in human history and also the first outward demonstration of the full implications of sin’s entry into the world. Ultimately, then, the devil is behind murder, just as he was behind Cain’s murder of Abel. When the hater kills, he shows himself to be a child of the devil (cf. 1 John 3:10). Once again, conduct is the clue to paternity.
7 tn The verb μένω (menw) in 3:15 refers to a spiritual reality (eternal life) which in this case does not reside in the person in question. To speak in terms of eternal life not “residing” in such an individual is not to imply that at some time in the past this person did possess eternal life and subsequently lost it, however. The previous verse (3:14) makes it clear that the individual under discussion here has “remained” in death (the realm of spiritual death) and so has never possessed eternal life to begin with, no matter what he may have claimed. Taken together with the use of μένω in 3:14, the use here implies that the opponents have “remained” in death all along, and have not ever been genuine believers. Thus “residing” rather than “remaining” is used as the translation for μένουσαν (menousan) here.
8 tn The ἵνα (Jina) clause in 4:21 could be giving (1) the purpose or (2) the result of the commandment mentioned in the first half of the verse, but if it does, the author nowhere specifies what the commandment consists of. It makes better sense to understand this ἵνα clause as (3) epexegetical to the pronoun ταύτην (tauthn) at the beginning of 4:21 and thus explaining what the commandment consists of: “that the one who loves God should love his brother also.”
9 tn See note on the phrase “fellow Christian” in 2:9.