5:13 I have written these things 2 to you who believe 3 in the name of the Son of God so that 4 you may know that you have eternal life.
1 tn Once more there is the familiar difficulty of determining whether the phrase refers (1) to what precedes or (2) to what follows. Here, because ἐν τούτῳ (en toutw) is followed by a clause introduced by ὅταν (Jotan) which appears to be related, it is best to understand ἐν τούτῳ as referring to what follows. The following ὅταν clause is epexegetical to ἐν τούτῳ, explaining how we know that we love God’s children: “by this we know that we love God’s children, whenever we love God and keep his commandments.”
2 tn Theoretically the pronoun ταῦτα (tauta) could refer (1) to what precedes or (2) to what follows. Since it is followed by a ἵνα (Jina) clause which gives the purpose for the writing, and a new subject is introduced in 5:14 (ἡ παρρησία, Jh parrhsia), it seems almost certain that the ταῦτα in 5:13 refers to preceding material. Even at this, some would limit the referent of ταῦτα (1) only to 5:1-12 or even 5:12, but more likely ταῦτα in 5:13 refers (2) to the entirety of the letter, for two reasons: (a) based on the structural analogy with the Gospel of John, where the conclusion refers to all that has preceded, it is probable that the conclusion to 1 John refers likewise to all that has preceded; and (b) the statement ταῦτα ἔγραψα ὑμῖν (tauta egraya Jumin) in 5:13 forms an inclusion with the statement καὶ ταῦτα γράφομεν ἡμεῖς (kai tauta grafomen Jhmei") at the end of the prologue (1:4) and encompasses the entire body of the letter.
3 tn The dative participle πιστεύουσιν (pisteuousin) in 5:13 is in simple apposition to the indirect object of ἔγραψα (egraya), ὑμῖν (Jumin), and could be translated, “These things I have written to you, namely, to the ones who believe in the name of the Son of God, in order that you may know.” There is an exact parallel to this structure in John 1:12, where the pronoun is αὐτοῖς (autois) and the participle is τοῖς πιστεύουσιν (toi" pisteuousin) as here.
4 tn This ἵνα (Jina) introduces a clause giving the author’s purpose for writing “these things” (ταῦτα, tauta), which refers to the entirety of the preceding material. The two other Johannine statements about writing, 1 John 1:4 and John 20:31, are both followed by purpose clauses introduced by ἵνα, as here.
5 tn The preposition ἐκ (ek) here indicates both source and possession: Christians are “from” God in the sense that they are begotten by him, and they belong to him. For a similar use of the preposition compare the phrases ἐκ τοῦ πατρός (ek tou patro") and ἐκ τοῦ κόσμου (ek tou kosmou) in 1 John 2:16.
6 tn The ἵνα (Jina) introduces a purpose clause which gives the purpose of the preceding affirmation: “we know that the Son of God has come and has given us insight (so that we may) know him who is true.”
7 sn The pronoun This one (οὗτος, Joutos) refers to a person, but it is far from clear whether it should be understood as a reference (1) to God the Father or (2) to Jesus Christ. R. E. Brown (Epistles of John [AB], 625) comments, “I John, which began with an example of stunning grammatical obscurity in the prologue, continues to the end to offer us examples of unclear grammar.” The nearest previous antecedent is Jesus Christ, immediately preceding, but on some occasions when this has been true the pronoun still refers to God (see 1 John 2:3). The first predicate which follows This one in 5:20, the true God, is a description of God the Father used by Jesus in John 17:3, and was used in the preceding clause of the present verse to refer to God the Father (him who is true). Yet the second predicate of This one in 5:20, eternal life, appears to refer to Jesus, because although the Father possesses “life” (John 5:26, 6:57) just as Jesus does (John 1:4, 6:57, 1 John 5:11), “life” is never predicated of the Father elsewhere, while it is predicated of Jesus in John 11:25 and 14:6 (a self-predication by Jesus). If This one in 5:20 is understood as referring to Jesus, it forms an inclusion with the prologue, which introduced the reader to “the eternal life which was with the Father and was manifested to us.” Thus it appears best to understand the pronoun This one in 5:20 as a reference to Jesus Christ. The christological affirmation which results is striking, but certainly not beyond the capabilities of the author (see John 1:1 and 20:28): This One [Jesus Christ] is the true God and eternal life.