1 Beloved, do not believe every spirit, but try the spirits whether they are of God, because many false prophets have gone out into the world. 2 By this you know the Spirit of God: every spirit that confesses that Jesus Christ has come in the flesh is from God, 3 And every spirit that does not confess that Jesus Christ has come in the flesh is not from God. And this is that spirit of antichrist, of which you have heard that it should come and even now already it is in the world. 4 You are of God, little children, and have overcome them, because greater is he who is in you than he who is in the world. 5 They are of the world; therefore, they speak from the world, and the world hears them. 6 We are of God. He who knows God hears us. He who is not of God does not hear us. By this we know the Spirit of truth and the spirit of error.
7 Beloved, let us love one another, for love is from God. And everyone who loves is born of God and knows God. 8 He who does not love does not know God, for God is love. 9 In this the love of God was manifested toward us: that God sent his only begotten Son into the world so that we might live through him. 10 In this is love, not that we loved God, but that he loved us and sent his Son to be the propitiation for our sins. 11 Beloved, if God loved us in this manner, we ought also to love one another. 12 No man has seen God at any time. If we love one another, God dwells in us and his love is perfected in us. 13 By this we know that we dwell in him and he in us: because he has given us of his Spirit. 14 And we have seen and testify that the Father sent the Son to be the Savior of the world.
15 Whoever confesses that Jesus is the Son of God, God dwells in him, and he in God. 16 And we have known and believed the love that God has to us. God is love. And he who dwells in love dwells in God, and God in him. 17 In this our love is made perfect so that we may have boldness in the day of judgment, because as he is, so are we in this world. 18 There is no fear in love. But perfect love casts out fear, because fear has torment. He who fears is not made perfect in love. 19 We love him because he first loved us. 20 If a man says, "I love God," and hates his brother, he is a liar. For he who does not love his brother whom he has seen, how can he love God whom he has not seen? 21 And this commandment we have from him: he who loves God must also love his brother.
[v.1a] - "do not believe every spirit" - In other words, "stop believing everything you hear." Not every teaching or person that comes to you claiming to be from God is from God. All things must be treated with discernment.
[v.1b] - "try" - That is, test or prove. Test the things you hear and prove them with the Scriptures whether or not they are true.