John calls us to "test the spirits" whether they are of God, for not every spirit is the Spirit of God; some spirits are of the Antichrist. We need to discern between the Spirit of truth and the spirit(s) of error which are at war in this world. The Christian takes great comfort that this is not a battle where the victory is uncertain, for God is sovereign. He has overcome evil, and so we with him. He who is in you is greater than he who is in the world.