It is critical for Christians to have the God-given ability to discern between the truth that comes from the Spirit of God, and error that comes from other spirits.  The believer's desperate need for discernment is heavily emphasized in both the Old and New Testaments.  Throughout the Bible we are continually warned against deception and the corruption that comes with it, because that is precisely the strategy of the kingdom of darkness.

God reveals truth in the world and Satan counters with lies.

THIS IS THE GREAT SPIRITUAL BATTLE.  If you want to know what is at the heart of true spiritual warfare, it is the battle between knowing right from wrong.  The ultimate in spiritual warfare is not chasing demons around.  Spiritual warfare is the battle for the mind.  It is the battle between fact and fiction.  The believer’s desperate need for discernment occupies the message of Scripture