He that doeth righteousness The Apostle shews here that newness of life is testified by good works; nor does that likeness of which he has spoken, that is between Christ and his members, appear, except by the fruits they bring forth; as though he had said, "Since it behooves us to be conformed to Christ, the truth and evidence of this must appear in our life." The exhortation is the same with that of Paul in Galatians "If ye live in the Spirit, walk also in the Spirit." (Galatians 5:25) For many would gladly persuade themselves that they have this righteousness buried in their hearts, while iniquity evidently occupies their feet, and hands, and tongue, and eyes.

Little children - Notes at 1-John 2:1.
Let no man deceive you - That is, in the matter under consideration; to wit, by persuading you that a man may live in sinful practices, and yet be a true child of God. From this it is clear that the apostle supposed there were some who would attempt to do this, and it was to counteract their arts that he made these positive statements in regard to the nature of true religion.
He that doeth righteousness is righteous - This is laid down as a great and undeniable principle in religion - a maxim which none could dispute, and as important as it is plain. And it is worthy of all the emphasis which the apostle lays on it. The man who does righteousness, or leads an upright life, is a righteous man, and no other one is. No matter how any one may claim that he is justified by faith; no matter how he may conform to the external duties and rites of religion; no matter how zealous he may be for orthodoxy, or for the order of the church; no matter what visions and raptures he may have, or of what peace and joy in his soul he may boast; no matter how little he may fear death, or hope for heaven - unless he is in fact a righteous man, in the proper sense of the term, he cannot be a child of God. Compare Matthew 7:16-23. If he is, in the proper sense of the word, a man who keeps the law of God, and leads a holy life, he is righteous, for that is religion. Such a man, however, will always feel that his claim to be regarded as a righteous man is not to be traced to what he is in himself, but to what he owes to the grace of God.
Even as he is righteous - See the notes at 1-John 3:3. Not necessarily in this world to the same degree, but with the same kind of righteousness. Hereafter he will become wholly free from all sin, like his God and Saviour, 1-John 3:2.

Let no man deceive you - Either by asserting that "you cannot be saved from sin in this life," or "that sin will do you no harm and cannot alter your state, if you are adopted into the family of God; for sin cannot annul this adoption." Hear God, ye deceivers! He that doeth righteousness is righteous, according to his state, nature, and the extent of his moral powers.
Even as he is righteous - Allowing for the disparity that must necessarily exist between that which is bounded, and that which is without limits. As God, in the infinitude of his nature, is righteous; so they, being filled with him, are in their limited nature righteous.

(7) Little children, let no man deceive you: he that doeth righteousness is righteous, even as he is righteous.
(7) Another argument of things joined together: He that lives justly, is just, and resembles Christ that is just, and by that is known to be the Son of God.

Little children, let no man deceive you,.... Neither by these doctrines, nor by wicked practices, drawing into the belief of the one, or into the performance of the other; suggesting, as the Gnostics did, that knowledge without practice was enough, and that it was no matter how a man lived, provided his notions of the Gospel were right:
he that doeth righteousness, is righteous; not that any man is made righteous by the works of the law, or by his obedience to the law of works, for this is contrary to the express word of God; and besides, the best righteousness of man is imperfect, and can never constitute or denominate him righteous before God; and was he justified by it; it would not only lay a foundation for boasting in him, which ought not to be, but would make the death, the sacrifice, and righteousness of Christ, to be in vain; men are only made righteous by the righteousness of Christ, which be has wrought out which is revealed in the Gospel, and received by faith, and which God imputes without works; so that he that doeth righteousness is he that being convinced of the insufficiency of his own righteousness, and of the excellency and suitableness of Christ's righteousness, renounces his own, and submits to his; who lays hold upon it, receives it, and exercises faith on it, as his justifying righteousness; and, in consequence of this, lives in a course of holiness and righteousness, in opposition to, and distinction from one that commits sin, or lives a sinful course of life; which, though it does not make him righteous in the sight of God, yet it shows him to be righteous in the sight of men, and proves that faith to be right which lays hold on the righteousness of Christ, by which he is truly righteous:
even as he is righteous; as Christ himself is righteous; and so the Syriac version reads; not as personal, or as he is personally and essentially righteous as God; but as mystical, every member of his body being clothed with the same robe of righteousness the whole body of Christ is, and indeed justified by the same righteousness that he as Mediator was, when he rose from the dead, as the representative of his people: moreover, as Christ showed himself to be righteous as man, by doing good, so believers in him, by imitating him, and walking as he walked, show themselves to be good and righteous, like, though not equal to him; for as a tree is known by its fruits, so is a good man by his good works, and a righteous man by doing righteousness; and as good fruit does not make a good tree, but shows it to be good, so good works do not make a good man, nor a man's own righteousness make him a righteous man, but show him to be so.

The same truth stated, with the addition that he who sins is, so far as he sins, "of the devil."
let no man deceive you--as Antinomians try to mislead men.
righteousness--Greek, "the righteousness," namely, of Christ or God.
he that doeth . . . is righteous--Not his doing makes him righteous, but his being righteous (justified by the righteousness of God in Christ, Romans 10:3-10) makes him to do righteousness: an inversion common in familiar language, logical in reality, though not in form, as in Luke 7:47; John 8:47. Works do not justify, but the justified man works. We infer from his doing righteousness that he is already righteous (that is, has the true and only principle of doing righteousness, namely, faith), and is therefore born of God (1-John 3:9); just as we might say, The tree that bears good fruit is a good tree, and has a living root; not that the fruit makes the tree and its root to be good, but it shows that they are so.
he--Christ.

Let no one deceive you - Let none persuade you that any man is righteous but he that uniformly practises righteousness; he alone is righteous, after the example of his Lord.