Verse 2. - This verso contains the main subject of the section. To confess the Incarnation is to prove that one draws one's inspiration from God through his Spirit. Know ye; or, recognize ye γινώσκετε, may be either imperative, in harmony with "believe" and "prove" (verse 1), or indicative, in harmony with "we know" (1 John 3:16, [19,] 24).

4:1-6 Christians who are well acquainted with the Scriptures, may, in humble dependence on Divine teaching, discern those who set forth doctrines according to the apostles, and those who contradict them. The sum of revealed religion is in the doctrine concerning Christ, his person and office. The false teachers spake of the world according to its maxims and tastes, so as not to offend carnal men. The world approved them, they made rapid progress, and had many followers such as themselves; the world will love its own, and its own will love it. The true doctrine as to the Saviour's person, as leading men from the world to God, is a mark of the spirit of truth in opposition to the spirit of error. The more pure and holy any doctrine is, the more likely to be of God; nor can we by any other rules try the spirits whether they are of God or not. And what wonder is it, that people of a worldly spirit should cleave to those who are like themselves, and suit their schemes and discourses to their corrupt taste?Hereby know ye the Spirit of God,.... This is a rule by which believers may know whether a man professing to have the Spirit of God, and to be called and sent by him, and whether the, doctrine he preaches, is of him or not:

every spirit that confesseth that Jesus Christ is come in the flesh,

is of God; or of the Spirit of God; that is, every doctrine which carries this truth in it; or every man that owns, and professes, and publishes this doctrine concerning Christ, is on the side of God and truth; and which contains several articles in it, respecting the person and office of Christ; as that he existed before he came in the flesh, not in the human nature, or as man, or as an angel, but as the Son of God, as a divine person, being truly and properly God; so that this confession takes in his divine sonship, and proper deity, and also his true and real humanity; that the Messiah was incarnate, against the Jews, and was God and man in one person; and that he was really man, and not in appearance only, against the heretics of those times: and it also includes his offices, as that Jesus of Nazareth was the Christ, the Messiah, which the Jews denied, and that he was the anointed prophet, priest, and King; and so is a confession or acknowledgment of all the doctrines of the Gospel, which came by him, as a prophet; and of his satisfaction, sacrifice, and intercession, as a priest; and of all his ordinances and commands as a King; and that he is the only Saviour and Redeemer of men. Now, whoever owns and declares this system of truth, "is of God"; not that everyone that assents unto this, or preaches it, is born of God; a man may believe, and confess all this, as the devils themselves do, and yet be destitute of the grace of God; but the spirit, or doctrine, which contains these things in it, is certainly of God, or comes from him; or whoever brings these truths with him, and preaches them, he is, so far as he does so, on the side of God and truth, and to be regarded.