2:8 On the other hand, I am writing a new commandment to you which is true in him 1 and in you, because 2 the darkness is passing away and the true light is already shining. 3 2:9 The one who says he is in the light but still hates 4 his fellow Christian 5 is still in the darkness. 2:10 The one who loves his fellow Christian 6 resides in the light, and there is no cause for stumbling in him. 7
2 tn The clause beginning with ὅτι (Joti) is often taken as (1) epexegetical or (2) appositional to the commandment (ἐντολήν, entolhn) giving a further explanation or clarification of it. But the statement following the ὅτι is about light and darkness, and it is difficult to see how this has anything to do with the commandment, especially as the commandment is related to the “new commandment” of John 13:34 for believers to love one another. It is far more likely that (3) the ὅτι clause should be understood as causal, but this still does not answer the question of whether it offers the reason for writing the “new commandment” itself or the reason for the relative clause (“that is true in him and in you”). It probably gives the reason for the writing of the commandment, although R. E. Brown (Epistles of John [AB], 268) thinks it refers to both.
3 sn The reference to the darkness…passing away and the true light…already shining is an allusion to John 1:5, 1:9, and 8:12. Because the author sees the victory of light over darkness as something already begun, he is writing Jesus’ commandment to love one another to the readers as a reminder to (1) hold fast to what they have already heard (see 1 John 2:7) and (2) not be influenced by the teaching of the opponents.
4 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.
5 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.
7 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.