A digression. The reference to the Spirit (1 John 3:24) reminds John that some who claimed to possess the Spirit of God, e.g. the false prophets, did so unjustifiably. Hence his readers must have a token whereby they may discriminate between true prophets and false. That token was the nature of their testimony concerning Christ. Thus the Spirit of truth or of Christ could be distinguished from that of error or Antichrist.
1 John 4:1. prove the spirits: the primitive Church, as we learn from 1 Corinthians 12-14 *, was rich in activities and experiences attributed to the operation of the Holy Spirit. At the same time evil spirits were believed to exist and to take possession of human beings, producing phenomena outwardly akin to those due to the Spirit of God. Hence some mode of distinguishing the two operations was needed (for which reason discernings of spirits is mentioned in 1 Corinthians 12:10 as one of the charisms). In the case of men claiming the inspired and exalted type of utterance known as prophesying the test suggested here is the orthodoxy of their message as regards the person of Christ (in 1 Corinthians 12:3 it is the confession of the lordship of Jesus). A prophet to be genuine, says John, must proclaim the reality of the Incarnation, the true union in Jesus of the human and the Divine. gone out: i.e. from the Church into the world (1 John 2:19).
1 John 4:2. confesseth. flesh: other possible translations are confesseth Jesus as Christ come in the flesh, and confesseth Jesus Christ as come in the flesh. In any case the double name suggests the two sides of our Lord's nature, both being contained in His historic Person. The Incarnation was, therefore, real, and not, as the Docetists taught, merely apparent.
1 John 4:3. confesseth not Jesus: i.e. in the sense just named. A different, but well attested, reading gives us Every spirit which annulleth Jesus, i.e. breaks up, as Cerinthus (cf. Introd.) did, the unity of His Divine-human Person. heard: i.e. in apostolic teaching (cf. 1 John 2:18). in the world already: it had found a home outside the Church in the non-Christian section of society. For world in this sense, see 1 John 2:15 *.
1 John 4:4. he that is in you: i.e. the Spirit of God, who, as the Spirit of truth, is greater than the spirit of error which is in the world. Hence false teaching, to which the world listens with sympathy, is rejected by the Church.
John returns to the theme of 1 John 3:14 ff., be cause if the Church is the home of truth, still more is it the home of love. The evidence for our Divine sonship is that the love manifested by God in sending His Son for our redemption a fact to which the Church bears witness issues in love on our part to God and to our brethren; love, when mature, casts out fear. Moreover the proof that we love the unseen God is that we love our brother, as Christ commanded us.
1 John 4:7. love is of God: i.e. is so peculiarly His product, answering to the deepest thing in His nature, that the lack of love proves that we have no real knowledge of God or kinship to Him.
1 John 4:12. Though we have no direct proof of God's existence and indwelling, we can know of His presence within us by the brotherly love which it creates (cf. 1 John 4:16; 1 John 3:24; Galatians 5:22). This is the inward, as Jesus was the outward (John 1:18), manifestation of the invisible God. his love: probably the love which He seeks to create within us. That love attains full development.
1 John 4:14-16. With love to the brethren John links belief in the reality of the Incarnation as evidence of God's indwelling in the soul.
1 John 4:16 a. in us: i.e. towards us (cf. 1 John 4:9). We in 1 John 4:14; 1 John 4:16 refers primarily to the apostle and his circle of witnesses. They are convinced of the reality of God's love, because they are convinced of the reality of the Incarnation.
1 John 4:17. Herein: i.e. by the mutual indwelling of God and the believer. made perfect: reaches perfect expression. that. judgement: judgment was always associated with the return of Christ (Matthew 25:31). Hence the thought here is parallel to that in 1 John 2:28.
1 John 4:17 b. Christ is with the Father, whilst we are in this world. With that difference love makes Him and us akin.
1 John 4:18. fear hath punishment: the idea that fear itself is a form of punishment may be present, but the context (day of judgement) requires the interpretation that fear implies a consciousness of shortcoming and a consequent expectation of punishment. Where love is perfected, no such expectation can exist.
1 John 4:20. hateth his brother: love to God and hatred of our fellow-Christians cannot coexist. The latter disproves the former.