The Bible, in the New Testament, shows Jesus casting out demons. If Jesus cast out demons then there is nothing wrong with Christians in the New Testament Church casting out demons. We are supposed to imitate the ministry of Jesus Christ as He was and is our example. There is nothing wrong with having your favorite Bible teacher, Pastor or Bishop, however, Jesus is the One that we are supposed to ultimately follow.
Not only was Jesus able to cast out demons but so were his disciples.
The following scripture show that power of Jesus and His ability to cast out demons and that the demons were ALWAYS subject to Him. But the Bible shows that they were also subject to the disciples.
Matthew 8:16 …they brought to Him [Jesus] many who were demon-possessed. And He cast out the spirits with a word, and healed all who were sick
Mark 1:23-27 Now there was a man in their synagogue with an unclean spirit. And he cried out, saying, “Let us alone! What have we to do with You, Jesus of Nazareth? Did You come to destroy us? I know who You are — the Holy One of God!” But Jesus rebuked him, saying, “Be quiet, and come out of him!” And when the unclean spirit had convulsed him and cried out with a loud voice, he came out of him. Then they were all amazed, so that they questioned among themselves, saying, “What is this? What new doctrine is this? For with authority He [Jesus] commands even the unclean spirits, and they obey Him.”
Matthew 8:28-33 When He [Jesus] had come to the other side, to the country of the Gergesenes, there met Him two demon-possessed men, coming out of the tombs, exceedingly fierce, so that no one could pass that way. And suddenly they cried out, saying, “What have we to do with You, Jesus, You Son of God? Have You come here to torment us before the time?” Now a good way off from them there was a herd of many swine feeding. So the demons begged Him, saying, “If You cast us out, permit us to go away into the herd of swine.” And He said to them, “Go.” So when they had come out, they went into the herd of swine. And suddenly the whole herd of swine ran violently down the steep place into the sea, and perished in the water. Then those who kept them fled; and they went away into the city and told everything, including what had happened to the demon-possessed men.
Mark 3:15,16 Then He [Jesus] appointed twelve, that they might be with Him and that He might send them out to preach, and to have power to heal sicknesses and to cast out demons:
Matthew 10:1 And when He [Jesus] had called His twelve disciples to Him, He gave them power over unclean spirits, to cast them out, and to heal all kinds of sickness and all kinds of disease.
Mark 6:7 And He [Jesus] called the twelve to Himself, and began to send them out two by two, and gave them power over unclean spirits.
The Body of Christ should always incorporate the full gospel in their ministry to the saints.