[5:11] 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.”
[5:11] 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.
[5:12] 3 sn The one who has the Son. The expression “to have the Son” in 5:12 means to “possess” him in the sense that he is present in the individual’s life (see 1 John 2:23 for the use of the Greek verb “to have” to indicate possession of a divine reality). From the parallel statement in 5:10a it is clear that believing in the Son and thus having God’s testimony in one’s self is the same as “having” the Son here in 5:12a. This is essentially identical to John 3:16: “that whoever believes in him should not perish but have eternal life.” In contrast, the negative statement in 5:12b reflects the author’s evaluation of the opponents: “the one who does not have the Son does not have (eternal) life.” The opponents, in spite of their claims to know God, do not possess (nor have they at any time possessed, cf. 2:19) eternal life.