Mark 16:17, “And these signs shall follow them that believe; In my name shall they cast out devils; they shall speak with new tongues.”

Notice how Jesus makes it clear that we are to cast out the spirits using His name. Now if we look into the early church, we see Paul using Jesus’ name to drive an evil spirit out of a woman:

Acts 16:18, “And this did she many days. But Paul, being grieved, turned and said to the spirit, I command thee in the name of Jesus Christ to come out of her. And he came out the same hour.”

Not only did the early church drive out evil spirits with Jesus’ name, but many were also healed using the name of Jesus:

Acts 4:30, “By stretching forth thine hand to heal; and that signs and wonders may be done by the name of thy holy child Jesus.”

The disciples even found somebody who was not a disciple, that was using Jesus’ name to cast out evil spirits:

Mark 9:38-39, “And John answered him, saying, Master, we saw one casting out devils in thy name, and he followeth not us: and we forbade him, because he followeth not us. But Jesus said, Forbid him not: for there is no man which shall do a miracle in my name, that can lightly speak evil of me.”