1 sn The person who practices sin is of the devil. 1 John 3:10 and John 8:44 might be cited as parallels, because these speak of opponents as the devil’s “children.” However, it is significant that the author of 1 John never speaks of the opponents as “fathered by the devil” in the same sense as Christians are “fathered by God” (3:9). A concept of evildoers as “fathered” by the devil in the same sense as Christians are fathered by God would imply a much more fully developed Gnosticism with its dualistic approach to humanity. The author of 1 John carefully avoids saying that the opponents are “fathered by the devil,” because in Johannine theology not to be fathered by God is to be fathered only by the flesh (John 1:13). This is a significant piece of evidence that 1 John predates the more fully developed Gnosticism of the 2nd century. What the author does say is that the opponents (“the one who practices sin”) are from the devil, in the sense that they belong to him and have given him their allegiance.
2 tn The present tense verb has been translated as an extending-from-past present (a present of past action still in progress). See ExSyn 520.
3 tn Here εἰς τοῦτο (eis touto) states the purpose for the revelation of God’s Son. However, the phrase offers the same difficulty as all the ἐν τούτῳ (en toutw) phrases in 1 John: Does it refer to what precedes or to what follows? By analogy with the ἐν τούτῳ construction it is probable that the phrase εἰς τοῦτο here refers to what follows: There is a ἵνα (Jina) clause following which appears to be related to the εἰς τοῦτο, and in fact is resumptive (that is, it restates the idea of “purpose” already expressed by the εἰς τοῦτο). Thus the meaning is: “For this purpose the Son of God was revealed: to destroy the works of the devil.”
4 tn In the Gospel of John λύσῃ (lush) is used both literally and figuratively. In John 1:27 it refers to a literal loosing of one’s sandal-thong, and in John 2:19 to a destruction of Jesus’ physical body which was understood by the hearers to refer to physical destruction of the Jerusalem temple. In John 5:18 it refers to the breaking of the Sabbath, in John 7:23 to the breaking of the law of Moses, and in John 10:35 to the breaking of the scriptures. The verb is again used literally in John 11:44 at the resurrection of Lazarus when Jesus commands that he be released from the graveclothes with which he was bound. Here in 1 John 3:8 the verb means, with reference to “the works of the devil,” to “destroy, bring to an end, abolish.” See BDAG 607 s.v. λύω 4 and F. Büchsel, TDNT 4:336.
5 tn Once again there is the problem of determining whether the phrase ἐν τούτῳ (en toutw) refers (1) to what precedes or (2) to what follows. This is the first of 5 uses of the phrase in the present section (4:9, 10, 13, 17; 5:2). In this case (as also in the next two instances) there is a ὅτι (Joti) clause following which is related and which explains (i.e., which is epexegetical to) the phrase ἐν τούτῳ. Thus the meaning here is, “By this the love of God is revealed in us: that God has sent his only Son into the world in order that we might live through him.”
6 tn In terms of syntax the force of the genitive τοῦ θεοῦ (tou qeou) may be (1) objective, (2) subjective, or (3) both. The phrase occurs for the first time in the letter in 2:5. Here in 4:9 the epexegetical ὅτι (Joti) clause which follows makes it clear that this is a subjective genitive, emphasizing God’s love for us rather than our love for God, because it describes God’s action in sending his Son into the world.
7 tn This phrase is best understood as the equivalent of a dative of sphere, but this description does not specify where the love of God is revealed with regard to believers: “in our midst” (i.e., among us) or “within us” (i.e., internally within believers). The latter is probable, because in the context the concept of God’s indwelling of the believer is mentioned in 4:12: “God resides (μένει, menei) in us.”
8 sn Although the word translated one and only (μονογενής, monogenhs) is often rendered “only begotten,” such a translation is misleading, since in English it appears to express a metaphysical relationship. The word in Greek was used of an only child (a son [Luke 7:12, 9:38] or a daughter [Luke 8:42]). It was also used of something unique (only one of its kind) such as the mythological bird called the Phoenix (1 Clement 25:2). From here it passes easily to a description of Isaac (Heb 11:17 and Josephus, Ant. 1.13.1 [1.222]) who was not Abraham’s only son, but was one-of-a-kind because he was the child of the promise. Thus the word means “one-of-a-kind” and is reserved for Jesus alone in the Johannine literature of the NT. While all Christians are children of God (τέκνα θεοῦ, tekna qeou), Jesus is God’s Son in a unique, one-of-a-kind sense. The word is used in this way in all its uses in the Gospel of John (1:14, 18; 3:16, 18).