Then certain of the vagabond Jews, exorcists, took upon them to call over them which had evil spirits the name of the Lord Jesus, saying, We adjure you by Jesus whom Paul preacheth. And there were seven sons of one Sceva, a Jew, and chief of the priests, which did so. And the man in whom the evil spirit was leaped on them, and overcame them, and prevailed against them, so that they fled out of that house naked and wounded. The Bible clearly gives a stern warning about going into spiritual warfare and not being born again. These men were exorcists, yet not saved.
Exorcism is done in different parts of the world by unsaved men.
In India, to drive out an evil spirit, men will beat a person that has an evil spirit, in thought that an evil spirit will not live in a person so badly beaten. In this case, Satan will allow an evil spirit to leave, since the purpose of it has been served. The second warning that I would like to stress is an ignorance of the enemy. There are two extremes a Christian must avoid at all costs. The first extreme is an ignorance of the enemy.