How do you cast out Demons?

Casting out demons

What is needed to cast out demons? One word... authority! Who has such authority? God's children... the believers! How do we exercise our authority? Through a spoken command in faith directed at the unclean spirits. The more faith we have, the more authority we can exercise.
Spiritual authority
Jesus sent us fourth into the world as He was sent fourth (John 20:21), to do the works He did (John 14:12), and He gave us the authority to do the work at hand (Mark 13:34).
What does it take to drive out demons? Authority! As we can see in Mark 1:27, "And they were all amazed, insomuch that they questioned among themselves saying, What thing is this? what new doctrine is this? for with authority commandeth he even the unclean spirits, and they do obey him." As we can see in Luke 4:35, Jesus was not afraid to exercise His authority either, "And Jesus rebuked him, saying, Hold thy peace, and come out of him. And when the devil had thrown him in the midst, he came out of him, and hurt him not."
Luke 10:17-19, "And the seventy returned again with joy, saying, Lord, even the devils are subject unto us through thy name. And he said unto them, I beheld Satan as lightning fall from heaven. Behold, I give unto you power (translates to AUTHORITY) to tread on serpents and scorpions, and over all the power of the enemy: and nothing shall by any means hurt you."
Does every believer have authority over demons? Yes! We are all seated with Christ in the heavenly realm (Eph 2:6), which means we are above the demons in rank of authority! Mark 13:34 also tells us how we are given authority to carry out the work that is laid before us. Mark 16:17 tells us that them who believe will be casting out demons.
The importance of "In the name of Jesus"
How did Jesus' disciples go about casting out demons? Through His name. Luke 10:17 tells us, "And the seventy returned again with joy, saying, Lord, even the devils are subject unto us through thy name."
How did the early church go about casting out demons? Through His name. Acts 16:18 tells us a story where Paul, "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."
How are the believers today supposed to be casting out demons? Through His name. As we can see in Mark 16:17, "these signs shall follow them that believe; In my name shall they cast out devils."
Authority is exercised through faith
Matthew 17:19-20, "Then came the disciples to Jesus apart, and said, Why could not we cast him out? And Jesus said unto them, Because of your unbelief..." Obviously they had the authority, but they weren't able to use it because their level of faith wasn't high enough to access the level of authority that needed to be exercised to drive out that particular kind of unclean spirit. Some evil spirits are stronger and harder to drive out, and sometimes prayer and fasting is necessary to build our faith up so we can drive them out, as we can see in the next verse (21), "Howbeit this kind goeth not out but by prayer and fasting."
Conclusion
As believers, we have been given authority in Jesus' name to drive out demons. We access our authority through faith and exercise our authority with a spoken command directed at the unclean spirit. As Paul clearly demonstrates in Acts 16:18, "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."
How does all this apply to us today? Mark 16:17 tells us, "These signs shall follow them that believe; In my name shall they cast out devils."