The apostle, having said that God's dwelling in and with us may be known by the Spirit that he hath given us, intimates that that Spirit may be discerned and distinguished from other spirits that appear in the world; and so here,
I. He calls the disciples, to whom he writes, to caution and scrutiny about the spirits and spiritual professors that had now risen. 1. To caution: ldblquote Beloved, believe not every spirit; regard not, trust not, follow not, every pretender to the Spirit of God, or every professor of vision, or inspiration, or revelation from God.
dblquote Truth is the foundation of simulation and counterfeits; there had been real communications from the divine Spirit, and therefore others pretended thereto. God will take the way of his own wisdom and goodness, though it may be liable to abuse; he has sent inspired teachers to the world, and given us a supernatural revelation, though others may be so evil and so impudent as to pretend the same; every pretender to the divine Spirit, or to inspiration, and extraordinary illumination thereby, is not to be believed. Time was when the spiritual man (the man of the Spirit, who made a great noise about, and boast of, the Spirit) was mad, Hosea 9:7. 2. To scrutiny, to examination of the claims that are laid to the Spirit: But try the spirits, whether they be of God, 1 John 4:1. God has given of his Spirit in these latter ages of the world, but not to all who profess to come furnished therewith; to the disciples is allowed a judgment of discretion, in reference to the spirits that would be believed and trusted in the affairs of religion. A reason is given for this trial: Because many false prophets have gone out into the world, 1 John 4:1. There being much about the time of our Saviour's appearance in the world a general expectation among the Jews of a Redeemer to Israel, and the humiliation, spiritual reformation, and sufferings of the Saviour being taken as a prejudice against him, others were induced to set up as prophets and messiahs to Israel, according to the Saviour's prediction, Matthew 24:23, Matthew 24:24. It should not seem strange to us that false teachers set themselves up in the church: it was so in the apostles' times; fatal is the spirit of delusion, sad that men should vaunt themselves for prophets and inspired preachers that are by no means so!
II. He gives a test whereby the disciples may try these pretending spirits. These spirits set up for prophets, doctors, or dictators in religion, and so they were to be tried by their doctrine; and the test whereby in that day, or in that part of the world where the apostle now resided (for in various seasons, and in various churches, tests were different), must be this: Hereby know you the Spirit of God, Every spirit that confesseth that Jesus Christ has come in the flesh (or that confesseth Jesus Christ that came in the flesh ), is of God, 1 John 4:2. Jesus Christ is to be confessed as the Son of God, the eternal life and Word, that was with the Father from the beginning; as the Son of God that came into, and came in, our human mortal nature, and therein suffered and died at Jerusalem. He who confesses and preaches this, by a mind supernaturally instructed and enlightened therein, does it by the Spirit of God, or God is the author of that illumination. On the contrary, ldblquote Every spirit that confesseth not that Jesus Christ has come in the flesh (or Jesus Christ that came in the flesh ) is not of God, 1 John 4:3. God has given so much testimony to Jesus Christ, who was lately here in the world, and in the flesh (or in a fleshly body like ours), though now in heaven, that you may be assured that any impulse or pretended inspiration that contradicts this is far from being from heaven and of God.
dblquote The sum of revealed religion is comprehended in the doctrine concerning Christ, his person and office. We see then the aggravation of a systematic opposition to him and it. And this is that spirit of antichrist whereof you have heard that it should come, and even now already is it in the world, 1 John 4:3. It was foreknown by God that antichrists would arise, and antichristian spirits oppose his Spirit and his truth; it was foreknown also that one eminent antichrist would arise, and make a long and fatal war against the Christ of God, and his institution, and honour, and kingdom in the world. This great antichrist would have his way prepared, and his rise facilitated, by other less antichrists, and the spirit of error working and disposing men's minds for him: the antichristian spirit began betimes, even in the apostles' days. Dreadful and unsearchable is the judgment of God, that persons should be given over to an antichristian spirit, and to such darkness and delusion as to set themselves against the Son of God and all the testimony that the Father hath given to the Son! But we have been forewarned that such opposition would arise; we should therefore cease to be offended, and the more we see the word of Christ fulfilled the more confirmed we should be in the truth of it