The Devil goes around counterfeiting many works of God. He has the ability to do that and deceive many people including leading Christians. The only attribute of God he cannot counterfeit is love. Why? Because "God is love"!. The Devil can counterfeit some of God's ways and powers but he cannot counterfeit God himself - who is love. You want to tell the difference between true Christians, those who manifest the attributes of God and those are just for the name of it? See which of the individuals have love for fellow people and brethren and those that do not.