Why do people cheat in the name of God?

Every man whether he is rich or poor will have his own problems.If a man says he is messenger of God and he can solve the problems of people, then people will approach him and he some how make those people to believe him and started to do some magic and get money.Meanwhile by virtue of time factor the problem would have reduced.Then that man become saint and being followed blindly by people.They will cheat till their colour come to light or till people are getting awareness.