John wrote his letter that those who read it might learn what it means to have real fellowship with God and make John's joy complete. Of all the letters in the New Testament, I John is probably one of the best for new Christians to study.
I John 2:26-27 (ESV)
I write these things to you about those who are trying to deceive you. But the anointing that you received from him abides in you, and you have no need that anyone should teach you. But as his anointing teaches you about everything, and is true, and is no lie -- just as it has taught you, abide in him.
I John 2:28-29 (ESV)
And now, little children, abide in him, so that when he appears we may have confidence and not shrink from him in shame at his coming. If you know that he is righteous, you may be sure that everyone who practices righteousness has been born of him.
I John 2:28-3:3 (ESV)
And now, little children, abide in him, so that when he appears we may have confidence and not shrink from him in shame at his coming. If you know that he is righteous, you may be sure that everyone who practices righteousness has been born of him. See what kind of love the Father has given to us, that we should be called children of God; and so we are. The reason why the world does not know us s that it did not know him. Beloved, we are God's children now, and what we will be has not yet appeared; but we know that when he appears we shall be like him, because we shall see him as he is. And everyone who thus hopes in him purifies himself as he is pure.
I John 3:4-10 (ESV)
Everyone who makes a practice of sinning also practices lawlessness; sin is lawlessness. You know that he appeared to take away sins, and in him there is no sin. No one who abides in him keeps on sinning; no one who keeps on sinning has either seen him or known him. Little children, let no one deceive you. Whoever practices righteousness is righteous, as he is righteous. Whoever makes a practice of sinning is of the devil, for the devil has been sinning from the beginning. The reason the Son of God appeared was to destroy the works of the devil. No one born of God makes a practice of sinning, for God's seed abides in him, and he cannot keep on sinning because he has been born of God. By this it is evident who are the children of God, and who are the children of the devil: whoever does not practice righteousness is not of God, nor is the one who does not love his brother.
I John 3:11-15 (ESV)
For this is the message that you have heard from the beginning, that we should love one another. We should not be like Cain, who was of the evil one and murdered his brother. And why did he murder him? Because his own deeds were evil and his brother's righteous. Do not be surprised, brothers that the world hates you. We know that we have passed out of death into life, because we love the brothers. Whoever does not love abides in death. Everyone who hates his brother is a murderer, and you know that no murderer has eternal life abiding in him.
I John 3:16-18 (ESV)
By this we know love, that he laid down his life for us, and we ought to lay down our lives for the brothers. But if anyone has the world's goods and sees his brother in need, yet closes his heart against him, how does God's love abide in him? Little children, let us not love in word or talk but in deed and in truth.
I John 3:19-24 (ESV)
But this we shall know that we are of the truth and reassure our heart before him; for whenever our heart condemns us, God is greater than our heart, and he knows everything. Beloved, if our heart does not condemn us, we have confidence before God; and whatever we ask we receive from him, because we keep his commandments and do what pleases him. And this is his commandment, that we believe in the name of his Son Jesus Christ and love on another, just as he has commanded us. Whoever keeps his commandments abides in God, and God in him. And by this we know that he abides in us, by the Spirit whom he has given us.
I John 4:1-6 (ESV)
Beloved, do not believe every spirit, but test the spirits to see whether they are from God, for many false prophets have gone out into the world. By this you know the Spirit of God: every spirit that confesses that Jesus Christ has come in the flesh is from God, and every spirit that does not confess Jesus is not from God. This is the spirit of the antichrist, which you heard was coming and now is in the world already. Little children, you are from God and have overcome them, for he who is in you is greater than he who is in the world. They are from the world; therefore they speak from the world, and the world listens to them. We are from God. Whoever knows God listens to us; whoever is not from God does not listen to you. By this we know the Spirit of truth and the spirit of error.
I John 4:7-12 (ESV)
Beloved, let us love one another, for love is from God, and whoever loves has been born of God and knows God. Anyone who does not love does not love God, because God is love. In this the love of God was made manifest among us, that God sent his only Son into the world, so that we might live through him. In this is love, not that we have loved God but that he loved us and sent his Son to be the propitiation for our sins. Beloved, if God so loved us, we also ought to love one another. No one has ever seen God; if we love one another, God abides in us and his love is perfected in us.
I John 4:13-16 (ESV)
By this we know that we abide in him and he in us, because he has given us of his Spirit. And we have seen and testify that the Father has sent his Son to be the Savior of the world. Whoever confesses that Jesus is the Son of God, God abides in him, and he in God. So we have come to know and to believe the love that God has for us. God is love, and whoever abides in love abides in God, and God abides in him.