[4:12] 1 sn An allusion to John 1:18.
[4:12] 2 tn The phrase “God resides in us” (ὁ θεὸς ἐν ἡμῖν μένει, Jo qeo" en Jhmin menei) in 4:12 is a reference to the permanent relationship which God has with the believer. Here it refers specifically to God’s indwelling of the believer in the person of the Holy Spirit, as indicated by 4:13b. Since it refers to state and not to change of status it is here translated “resides” (see 2:6).
[4:12] 3 tn The phrase “his [God’s] love is perfected (τετελειωμένη ἐστίν, teteleiwmenh estin) in us” in 4:12 is difficult. First it is necessary to decide whether αὐτοῦ (autou), which refers to God, is (1) subjective (God’s love for us) or (2) objective (our love for God). It is clear that a subjective genitive, stressing God’s love for us, is in view here, because the immediate context, 4:11a, has believers as the objects of God’s love (ὁ θεὸς ἠγάπησεν ἡμᾶς, Jo qeo" hgaphsen Jhma"). The entire phrase ἡ ἀγάπη αὐτοῦ ἐν ἡμῖν τετελειωμένη ἐστίν (Jh agaph autou en Jhmin teteleiwmenh estin) then refers to what happens when believers love one another (note the protasis of the conditional sentence in 4:12, ἐάν ἀγαπῶμεν ἀλλήλους [ean agapwmen allhlou"]). The love that comes from God, the love that he has for us, reaches perfection in our love for others, which is what God wants and what believers are commanded to do (see 3:23b).
[4:13] 4 tn Again whether the referent of the phrase ἐν τούτῳ (en toutw) (1) precedes or (2) follows is a problem. This time there are two ὅτι (Joti) clauses which follow. The first is an indirect discourse clause related to γινώσκομεν (ginwskomen) and giving the content of what believers know: “that we reside in him and he in us.” The second ὅτι clause is epexegetical (or explanatory) to the ἐν τούτῳ phrase, explaining how believers know that they reside in God and God remains in them: “in that he has given us of his Spirit.”
[4:13] 5 tn Grk “in him.” Context indicates that the pronoun refers to God (see 4:12).
[4:13] 6 sn The genitive of his Spirit here, like the phrase in 3:24, probably reflects a partitive nuance, so that the author portrays God as ‘apportioning’ his Spirit to individual believers. This leads to the important observation that the author is not particularly interested in emphasizing (1) the ongoing interior witness of the Holy Spirit (which is what the passage is often understood to mean) but is emphasizing (2) the fact that God has given the Spirit to believers, and it is this fact that gives believers assurance of their relationship to God. In other words, it is the fact that the Holy Spirit has been given to believers, rather than the ongoing interior testimony of the Holy Spirit within the believer, which is the primary source of the believer’s assurance.