Rather, “truly in him,” with the word for “truly” in the emphatic position in the Greek, to point the contrast to the false claims mentioned in v. 4.

 This may be love for God on the part of man, or God’s love as bestowed upon man. In this epistle John uses the phrase in both senses but appears to refer chiefly to God’s love for man (ch. 4:9; cf. chs. 3:1, 16, 17; 4:14, 16; but see chs. 2:15; 5:3). “Love is of God” (ch. 4:7). All true love comes from God, and he who is motivated to keep the Lord’s commands does so by virtue of love that is derived from God. For comment on “love” (agapē) see on Matt. 5:43, 44; 1 Cor. 13:1.

 Gr. teleioō, “to bring to an end,” “to complete,” “to perfect.” Instead of “is ... perfected” we should read “has been perfected.” For the adjective teleios see on Matt. 5:48.

 See on v. 3. In the present instance “hereby” may refer to the keeping of God’s word Word (v. 5), or to walking as Christ walked (v. 6). Both states give evidence of being in Christ.

 That is, in Christ. For comment on this phrase, which occurs frequently in the NT, see on 2 Cor. 5:17; Eph. 1:1; cf. on John 15:4; Gal. 2:20.

The apostle is not content to leave his readers with the negative picture, but immediately paints the positive aspect, to encourage the faithful.