1 See what love the Father has bestowed on us that we may be called the children of God. Yet so we are. The reason the world does not know us is that it did not know him.
Beloved, we are God’s children now; what we shall be has not yet been revealed. We do know that when it is revealed 2 we shall be like him, for we shall see him as he is.
Everyone who has this hope based on him makes himself pure, as he is pure.
Everyone who commits sin commits lawlessness, for sin is lawlessness. 3
You know that he was revealed to take away sins, and in him there is no sin.
No one who remains in him sins; no one who sins has seen him or known him.
Children, let no one deceive you. The person who acts in righteousness is righteous, just as he is righteous.
Whoever sins belongs to the devil, because the devil has sinned from the beginning. Indeed, the Son of God was revealed to destroy the works of the devil.
No one who is begotten by God commits sin, because God’s seed remains in him; he cannot sin because he is begotten by God. 4
In this way, the children of God and the children of the devil are made plain; no one who fails to act in righteousness belongs to God, nor anyone who does not love his brother.
5 For this is the message you have heard from the beginning: we should love one another,
unlike Cain who belonged to the evil one and slaughtered his brother. Why did he slaughter him? Because his own works were evil, and those of his brother righteous.
Do not be amazed, (then,) brothers, if the world hates you.
We know that we have passed from death to life because we love our brothers. Whoever does not love remains in death.
Everyone who hates his brother is a murderer, and you know that no murderer has eternal life remaining in him.
The way we came to know love was that he laid down his life for us; so we ought to lay down our lives for our brothers.
If someone who has worldly means sees a brother in need and refuses him compassion, how can the love of God remain in him?
Children, let us love not in word or speech but in deed and truth.
6 (Now) this is how we shall know that we 7 belong to the truth and reassure our hearts before him
in whatever our hearts condemn, for God is greater than our hearts and knows everything.
Beloved, if (our) hearts do not condemn us, we have confidence in God
and receive from him whatever we ask, because we keep his commandments and do what pleases him.
And his commandment is this: we should believe in the name of his Son, Jesus Christ, and love one another just as he commanded us.
Those who keep his commandments remain in him, and he in them, and the way we know that he remains in us is from the Spirit that he gave us.
1 [1-3] The greatest sign of God’s love is the gift of his Son (⇒ John 3:16) that has made Christians true children of God. This relationship is a present reality and also part of the life to come; true knowledge of God will ultimately be gained, and Christians prepare themselves now by virtuous lives in imitation of the Son.
2  When it is revealed: or “when he is revealed” (the subject of the verb could be Christ).
3  Lawlessness: a reference to the activity of the antichrist, so it is expressed as hostility toward God and a rejection of Christ. The author goes on to contrast the states of sin and righteousness. Christians do not escape sin but realize that when they sin they cease to have fellowship with God. Virtue and sin distinguish the children of God from the children of the devil.
4  A habitual sinner is a child of the devil, while a child of God, who by definition is in fellowship with God, cannot sin. Seed: Christ or the Spirit who shares the nature of God with the Christian.
5 [11-18] Love, even to the point of self-sacrifice, is the point of the commandment. The story of Cain and Abel (⇒ 1 John 3:12-15; ⇒ Genesis 4:1-16) presents the rivalry of two brothers, in a contrast of evil and righteousness, where envy led to murder. For Christians, proof of deliverance is love toward others, after the example of Christ. This includes concrete acts of charity, out of our material abundance.
6 [19-24] Living a life of faith in Jesus and of Christian love assures us of abiding in God no matter what our feelings may at times tell us. Our obedience gives us confidence in prayer and trust in God’s judgment. This obedience includes our belief in Christ and love for one another.
7 [19b-20] This difficult passage may also be translated “we shall be at peace before him in whatever our hearts condemn, for . . .” or “and before God we shall convince our hearts, if our hearts condemn us, that God is greater than our hearts.”