1 John 4:2-5

2By this ye know the Spirit of God: Every spirit that confesseth that Jesus Christ hath come in the flesh is from God: 3And every spirit that confesseth not that Jesus Christ is come in the flesh is not from God: and this is that spirit of antichrist, of which ye have heard that it should come; and even now already it is in the world.

4Ye are of God, little children, and have overcome them: because greater is he that is in you, than he that is in the world. 5They are of the world: therefore they speak from the world, and the world heareth them.