1 John 4 Revised Standard Version Catholic Edition (RSVCE)
Testing the Spirits
4 Beloved, do not believe every spirit, but test the spirits[a] to see whether they are of God; for many false prophets have gone out into the world. 2 By this you know the Spirit of God: every spirit which confesses that Jesus Christ has come in the flesh is of God, 3 and every spirit which does not confess Jesus is not of God. This is the spirit of antichrist, of which you heard that it was coming, and now it is in the world already. 4 Little children, you are of God, and have overcome them; for he who is in you is greater than he who is in the world. 5 They are of the world, therefore what they say is of the world, and the world listens to them. 6 We are of God. Whoever knows God listens to us, and he who is not of God does not listen to us. By this we know the spirit of truth and the spirit of error.
God Is Love
7 Beloved, let us love one another; for love is of God, and he 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 made manifest among us, that God sent his only 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 expiation for our sins. 11 Beloved, if God so loved us, we also ought to love one another. 12 No man has ever seen God; if we love one another, God abides in us and his love is perfected in us.
13 By this we know that we abide in him and he in us, because he has given us of his own Spirit. 14 And we have seen and testify that the Father has sent his Son as the Savior of the world. 15 Whoever confesses that Jesus is the Son of God, God abides in him, and he in God. 16 So we know and believe the love God has for us. God is love, and he who abides in love abides in God, and God abides in him. 17 In this is love perfected with us, that we may have confidence for 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. For fear has to do with punishment, and he who fears is not perfected in love. 19 We love, because he first loved us. 20 If any one says, “I love God,” and hates his brother, he is a liar; for he who does not love his brother whom he has seen, cannot[b] love God whom he has not seen. 21 And this commandment we have from him, that he who loves God should love his brother also.