See on v. 4. Here reference is to all who profess Christ, whether in sincerity or otherwise.

 Gr. menō, “to tarry,” “to continue to be present,” “to remain,” “to abide.” John makes frequent use of menō—41 times in his Gospel and 26 times in his epistles. In his writings it often has a mystic sense to indicate the union that exists between God and Christ (John 14:10) and the similar union that should exist between Christ and the believer (John 15:4-10; 1 John 2:24, 28; 3:6, 24). The phrase “abide in him” is John’s equivalent of Paul’s “to be in Christ” (see above under “in him,” v. 5). Although the phrase has a mystical meaning, it is also intensely practical and concerns the everyday life of the Christian.

 Gr. peripateō (see on Eph. 2:2), used commonly in the NT with reference to Christian conduct (cf. on 1 Thess. 2:12).

In His earthly life Jesus left a perfect example for all men to follow. The Christian needs to be thoroughly acquainted with that sinless life in order to copy it and apply its principles to conditions under which he himself must live. John insists that he who claims to abide in Christ should give daily evidence that he is emulating his Saviour. The life that he is emulating his Saviour. The life must tally with the profession (SC 58, 59).

 Gr. opheilō, “to owe,” with reference to debts (Matt. 18:28; etc.); “to be under obligation” to do something (John 13:14). John uses it four times in his epistles (here and in 1 John 3:16; 4:11; 3 John 8). In Biblical usage opheilō conveys a strong sense of moral obligation.