¹ tn The ὅτι (Joti) clause in 5:11 is epexegetical (explanatory) to the phrase καὶ αὕτη ἐστίν (kai Jauth estin) at the beginning of the verse and gives the content of the testimony for the first time: “And this is the testimony: that God has given us eternal life, and this life is in his Son.”

² sn In understanding how “God’s testimony” (added to the three witnesses of 5:8) can consist of eternal life it is important to remember the debate between the author and the opponents. It is not the reality of eternal life (whether it exists at all or not) that is being debated here, but rather which side in the debate (the author and his readers or the opponents) possesses it (this is a key point). The letter began with a testimony that “the eternal life” has been revealed (1:2), and it is consummated here with the reception or acknowledgment of that eternal life as the final testimony. This testimony (which is God’s testimony) consists in eternal life itself, which the author and the readers possess, but the opponents do not. This, for the author, constitutes the final apologetic in his case against the opponents.

³ 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.”

⁴ 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.