Heresies and cults have always threatened the church. When falsehoods are exposed, the church must do all it can to defend the truth. In his epistle to the Galatians, Paul is defending the truth of Christianity against false theology. Satan will use this to deceive people to believe what is untrue. He may use his demons to appear as angels to someone to give them a message when in reality he is giving them a message of lies and deception. We must be on guard against such evil and know the difference between the voice of God and the voice of Satan.