"The worldliness' in view here, as in 2:12-17, is primarily a wrong attitude: a determination to be anchored to a society which does not know God (cf. 3:1 . . .). But whereas in the earlier section John shows that worldly attitudes can be associated with material possessions and ambitions (the things of the world' as such; cf. 2:15, and the reference to pride in one's life style' at v 16), here the writer contrasts God and the world' chiefly in terms of truth and error . . ."140
"The battlefield is not so much the ecclesial community itself as the heart of the believer."141
John showed that a Christian's righteous behavior identifies him or her as a Christian (2:29-3:10a) and that love for the brethren and boldness in prayer characterize this behavior (3:10b-24). Next he pointed out that this behavior is a manifestation of God who indwells the believer.
4:1-3 It is necessary to distinguish the Spirit of God from false spirits (i.e., spirits advocating falsehood) because many false prophets have gone out into the world. False spirits (utterances or persons inspired by a spirit opposed to Christ) result in false teaching. John's test question whereby one can determine whether the Spirit of God or a spirit of falsehood possesses a person was this. What does the person believe about Jesus Christ? If a person denies the incarnation of Jesus Christ--a heresy false teachers were promoting among John's original readers--he has the spirit of antichrist (cf. 2:18-27). That is, a denial of the doctrine of Christ as the apostles taught it, deviation from orthodox Christology, evidences a spirit opposed to Jesus Christ.
"The test of the presence of the Divine Spirit is the confession of the Incarnation, or, more exactly, of the Incarnate Saviour. The Gospel centres in a Person and not in any truth, even the greatest, about the Person."142
4:4 John's readers had so far overcome these opponents of Jesus Christ by the Holy Spirit who indwelt them ("He who is in you;"cf. 3:24; 4:2, 13). The Holy Spirit is stronger than Satan ("he who is in the world"). We overcome Satan, his agents, and his influence as we resist his temptations to doubt, deny, disregard, and disobey the Word of God (1 Pet. 5:9; cf. Gen. 3; Matt. 4).143
4:5 The antichrists' teachings have an appeal to worldly minds because they come from the world and share the viewpoint of the world (cf. John 3:31).
"The term world (kosmos) is probably to be understood in two ways: as a system of thought antithetical to Christian belief and as a description of those members of the community who were led astray by the false teachers. That some members of the community were easily persuaded to forsake the truth of the gospel should not bewilder the faithful."144
"The word world' has several nuances of meaning; in verse 3 it means more the area inhabited by men, but in verse 4 it refers rather to sinful mankind, while in verse 5 the stress is more on the sinful principle found in such people"145
4:6 "We"probably refers to the apostolic eyewitnesses as elsewhere in this epistle, but it also includes the faithful. Those believers who "know"God intimately respond positively to the teaching of the apostles. By apostolic doctrine we know whether any teaching is truth or error, namely, having its source in the Holy Spirit or Satan. The way to distinguish truth from error is to compare it with what the Scriptures teach.
"When people confess that Jesus came in the flesh, when they hear God speak to them in the gospel of his Son and are obedient to it, then the Spirit of truth' has been present and active. When people deny the gospel, when they will not hear it as God's Word and will not confess that Jesus Christ has come in the flesh, then the spirit of falsehood' has been at work."146
"Since John issues warnings to his readers against being taken in by the false teachers (2:24; 2 Jn. 7-11), he appears to have reckoned with the possibility of true believers going astray."147
