1 Behold, what manner of love the Father hath bestowed upon us, that we should be called the sons of God: therefore the world knoweth us not, because it knew him not.
2 Beloved, now are we the sons of God, and it doth not yet appear what we shall be: but we know that, when he shall appear, we shall be like him; for we shall see him as he is.
3 And every man that hath this hope in him purifieth himself, even as he is pure.
4 Whosoever committeth sin transgresseth also the law: for sin is the transgression of the law.
5 And ye know that he was manifested to take away our sins; and in him is no sin.
6 Whosoever abideth in him sinneth not: whosoever sinneth hath not seen him, neither known him.
7 Little children, let no man deceive you: he that doeth righteousness is righteous, even as he is righteous.
8 He that committeth sin is of the devil; for the devil sinneth from the beginning. For this purpose the Son of God was manifested, that he might destroy the works of the devil.
9 Whosoever is born of God doth not commit sin; for his seed remaineth in him: and he cannot sin, because he is born of God.
10 In this the children of God are manifest, and the children of the devil: whosoever doeth not righteousness is not of God, neither he that loveth not his brother.
11 For this is the message that ye heard from the beginning, that we should love one another.
12 Not as Cain, who was of that wicked one, and slew his brother. And wherefore slew he him? Because his own works were evil, and his brother's righteous.
13 Marvel not, my brethren, if the world hate you.
14 We know that we have passed from death unto life, because we love the brethren. He that loveth not his brother abideth in death.
15 Whosoever hateth his brother is a murderer: and ye know that no murderer hath eternal life abiding in him.
16 Hereby perceive we the love of God, because he laid down his life for us: and we ought to lay down our lives for the brethren.
17 But whoso hath this world's good, and seeth his brother have need, and shutteth up his bowels of compassion from him, how dwelleth the love of God in him?
18 My little children, let us not love in word, neither in tongue; but in deed and in truth.
19 And hereby we know that we are of the truth, and shall assure our hearts before him.
20 For if our heart condemn us, God is greater than our heart, and knoweth all things.
21 Beloved, if our heart condemn us not, then have we confidence toward God.
22 And whatsoever we ask, we receive of him, because we keep his commandments, and do those things that are pleasing in his sight.
23 And this is his commandment, That we should believe on the name of his Son Jesus Christ, and love one another, as he gave us commandment.
24 And he that keepeth his commandments dwelleth in him, and he in him. And hereby we know that he abideth in us, by the Spirit which he hath given us.
The apostle admires the love of God in making believers his children. (1,2) The purifying influence of the hope of seeing Christ, and the danger of pretending to this, and living in sin. (3-10) Love to the brethren is the character of real Christians. (11-15) That love described by its actings. (16-21) The advantage of faith, love, and obedience. (22-24)1,2 Little does the world know of the happiness of the real followers of Christ. Little does the world think that these poor, humble, despised ones, are favourites of God, and will dwell in heaven. Let the followers of Christ be content with hard fare here, since they are in a land of strangers, where their Lord was so badly treated before them. The sons of God must walk by faith, and live by hope. They may well wait in faith, hope, and earnest desire, for the revelation of the Lord Jesus. The sons of God will be known, and be made manifest by likeness to their Head. They shall be transformed into the same image, by their view of him.3-10 The sons of God know that their Lord is of purer eyes than to allow any thing unholy and impure to dwell with him. It is the hope of hypocrites, not of the sons of God, that makes allowance for gratifying impure desires and lusts. May we be followers of him as his dear children, thus show our sense of his unspeakable mercy, and express that obedient, grateful, humble mind which becomes us. Sin is the rejecting the Divine law. In him, that is, in Christ, was no sin. All the sinless weaknesses that were consequences of the fall, he took; that is, all those infirmities of mind or body which subject man to suffering, and expose him to temptation. But our moral infirmities, our proneness to sin, he had not. He that abides in Christ, continues not in the practice of sin. Renouncing sin is the great proof of spiritual union with, continuance in, and saving knowledge of the Lord Christ. Beware of self-deceit. He that doeth righteousness is righteous, and to be a follower of Christ, shows an interest by faith in his obedience and sufferings. But a man cannot act like the devil, and at the same time be a disciple of Christ Jesus. Let us not serve or indulge what the Son of God came to destroy. To be born of God is to be inwardly renewed by the power of the Spirit of God. Renewing grace is an abiding principle. Religion is not an art, a matter of dexterity and skill, but a new nature. And the regenerate person cannot sin as he did before he was born of God, and as others do who are not born again. There is that light in his mind, which shows him the evil and malignity of sin. There is that bias upon his heart, which disposes him to loathe and hate sin. There is the spiritual principle that opposes sinful acts. And there is repentance for sin, if committed. It goes against him to sin with forethought. The children of God and the children of the devil have their distinct characters. The seed of the serpent are known by neglect of religion, and by their hating real Christians. He only is righteous before God, as a justified believer, who is taught and disposed to righteousness by the Holy Spirit. In this the children of God are manifest, and the children of the devil. May all professors of the gospel lay these truths to heart, and try themselves by them.11-15 We should love the Lord Jesus, value his love, and therefore love all our brethren in Christ. This love is the special fruit of our faith, and a certain sign of our being born again. But none who rightly know the heart of man, can wonder at the contempt and enmity of ungodly people against the children of God. We know that we are passed from death to life: we may know it by the evidences of our faith in Christ, of which love to our brethren is one. It is not zeal for a party in the common religion, or affection for those who are of the same name and sentiments with ourselves. The life of grace in the heart of a regenerate person, is the beginning and first principle of a life of glory, whereof they must be destitute who hate their brother in their hearts.16-21 Here is the condescension, the miracle, the mystery of Divine love, that God would redeem the church with his own blood. Surely we should love those whom God has loved, and so loved. The Holy Spirit, grieved at selfishness, will leave the selfish heart without comfort, and full of darkness and terror. By what can it be known that a man has a true sense of the love of Christ for perishing sinners, or that the love of God has been planted in his heart by the Holy Spirit, if the love of the world and its good overcomes the feelings of compassion to a perishing brother? Every instance of this selfishness must weaken the evidences of a man's conversion; when habitual and allowed, it must decide against him. If conscience condemn us in known sin, or the neglect of known duty, God does so too. Let conscience therefore be well-informed, be heard, and diligently attended to.22-24 When believers had confidence towards God, through the Spirit of adoption, and by faith in the great High Priest, they might ask what they would of their reconciled Father. They would receive it, if good for them. And as good-will to men was proclaimed from heaven, so good-will to men, particularly to the brethren, must be in the hearts of those who go to God and heaven. He who thus follows Christ, dwells in Him as his ark, refuge, and rest, and in the Father through him. This union between Christ and the souls of believers, is by the Spirit he has given them. A man may believe that God is gracious before he knows it; yet when faith has laid hold on the promises, it sets reason to work. This Spirit of God works a change; in all true Christians it changes from the power of Satan to the power of God. Consider, believer, how it changes thy heart. Dost not thou long for peace with God? Wouldst thou not forego all the world for it? No profit, pleasure, or preferment shall hinder thee from following Christ. This salvation is built upon Divine testimony, even the Spirit of God.Commentary by Matthew Henry, 1710.