1 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.”
2 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.
3 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.”
4 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).
5 tn Once again there is the (by now familiar) problem of determining whether the referent of this phrase (1) precedes or (2) follows. Here there are two ὅτι (Joti) clauses which follow, both of which are epexegetical to the phrase ἐν τούτῳ (en toutw) and explain what the love of God consists of: first, stated negatively, “not that we have loved God,” and then positively, “but that he loved us and sent his Son to be the atoning sacrifice for our sins.”
6 tn The two ὅτι (Joti) clauses are epexegetical to the phrase ἐν τούτῳ (en toutw) which begins the verse.
sn What is important (as far as the author is concerned) is not whether we love God (or say that we love God – a claim of the opponents is probably behind this), but that God has loved us and sent his Son to be the atoning sacrifice which removes believers’ sins. This latter point is similar to the point made in 2:2 and is at the heart of the author’s dispute with the opponents, because they were denying any salvific value to Jesus’ earthly life and ministry, including his death on the cross.
7 sn As explained at 2:2, inherent in the meaning of the word translated atoning sacrifice (ἱλασμός, Jilasmos) is the idea of turning away the divine wrath, so that “propitiation” is the closest English equivalent. God’s love for us is expressed in his sending his Son to be the propitiation (the propitiatory sacrifice) for our sins on the cross. This is an indirect way for the author to allude to one of the main points of his controversy with the opponents: the significance for believers’ salvation of Jesus’ earthly life and ministry, including especially his sacrificial death on the cross. The contemporary English “atoning sacrifice” communicates this idea more effectively.