Where do all the demons go?

During an Unbound training workshop, people will frequently ask me this question: 

Why don’t you send demons to a particular place when you command spirits to leave a person?

Many people have concerns about where an evil spirit will go and what it will do after the command is given. In order to address this concern, many models of deliverance ministry command the spirits to go to a particular place. 
Jesus’ teaching in Matthew 12 is often used as the basis for this type of command:
When an impure spirit comes out of a person, it goes through arid places seeking rest and does not find it. Then it says, ‘I will return to the house I left.’ When it arrives, it finds the house unoccupied, swept clean and put in order. Then it goes and takes with it seven other spirits more wicked than itself, and they go in and live there. And the final condition of that person is worse than the first. That is how it will be with this wicked generation.
If Jesus warns us that evil spirits can return, then wouldn’t it be helpful to send them someplace else? Or at least protect those who are in the vicinity from demonic attack?
If you examine the context of Jesus’ teaching, you will see that He is describing the condition of people who do not repent. Jesus is speaking about the ministry of the Pharisees, who drove out evil spirits by the use of a ritual but did not bring people into God’s kingdom. 
The Pharisees accused Jesus of driving out demons by the power of Beelzebul, but Jesus did it by the Spirit of God. The real danger that Jesus was referring to, that evil spirits could return and re-infest a person, was not because the spirits were sent into arid places, but because the person did not repent and receive the kingdom of God. In contrast to the Pharisees, who left the person as an “unoccupied house,” Jesus brought the kingdom of God to the person. Jesus said in Matthew 11:20, “But if I drive out demons by the finger of God, then the kingdom of God has come upon you.” The deliverance that Jesus brings prepares them for the abiding presence of the Holy Spirit. Therefore, a believer who is set free by the Spirit during an Unbound session is not an unoccupied house. 
The command we use in Unbound is:
“In the name of Jesus, I break the power of every spirit that ______ has renounced, and I command them to leave right now.” 
There are two reasons why we do not include a place in the command used in Unbound.
The first reason is that Jesus didn’t do it.
In most cases recorded in the Gospels, Jesus simply commanded spirits to leave the person, and He did not send them to a particular location. 
There is only one instance in the Gospels where it appears that Jesus sends a legion of demons to a particular place, namely, into a herd of pigs (Matthew 8:30-31). This was unusual and not a model for his disciples. It was not Jesus’ idea to send the demons into the nearby pigs. They begged Him for permission to go into the pigs. Jesus had the authority to cast out these spirits from anyone who came to Him, but He allowed them to go into the pigs which resulted in their destruction. In every other case Jesus focused on the person before Him and did not allow spirits to dialogue with Him. The issue at hand was the advancing kingdom of God coming upon a person.
The second reason is that there is no evidence that Jesus gave His disciples the authority to tell demons where to go, nor did He instruct them to do so.
Jesus gave authority to His disciples to preach the kingdom, heal the sick, and cast out demons. He did not explicitly give His disciples the authority to tell demons where to go. In the ministry of Jesus and His disciples, we see an emphasis on proclaiming the kingdom of God with demonstrations of power that dispel sickness, drive out spiritual darkness, and testify to the good news. It was clear through these signs that followed the believers that the reign of God was coming to all who responded to the gospel with faith.
Some Perspective on Demons 
Demons are fallen angels. They are pure spirits, which means they do not have bodies. They are not limited by time or space. When a person is held in bondage to an evil spirit, it does not mean that the evil spirit is confined to a person. The presence of evil spirits is connected to the presence of sin on the earth; that is what attracts them. 
Therefore, when we give the command in Unbound, evil spirits are not being released from a person and freed to go torment someone else. Instead, the person is being liberated and is now experiencing the kingdom of God in a greater way. In a very powerful way, when the spirit no longer has access to a person, it has become homeless, for there is no place of agreement in the person where it can reside. The kingdom of darkness recedes and the kingdom of God advances, one person at a time. I look forward to the day when all of God’s children can say with Jesus, “the prince of the world is coming, but he has no place in me” (John 14:30).
What spirits do after they leave is not our concern. Helping believers close the door to their influence is. The ultimate fate of every demon was sealed at the Cross, and the final destination of every evil spirit will be assigned by God and carried out by His angels. We do not want to go beyond the authority that Jesus gave us by assigning places for demons to dwell. We also do not want to engage in superstitious practices that are motivated by irrational fears.
In Unbound sessions, individuals who come for ministry exercise their faith through repentance, forgiveness, and renunciation. They cooperate with the Holy Spirit and surrender to His power. When the command is given, spirits that have held people in bondage must leave (or release their hold) because they no longer have permission to remain.
We should not be afraid to proclaim the good news, heal the sick, or cast out evil spirits. Like Jesus, we can make the people to whom we minister the focus of our attention and compassion. Commanding spirits to leave a person who no longer makes a home for them can be a source of joy, as we delight in the victory of Jesus and the knowledge that we belong to the Father. We can trust in the sovereignty of God as His will and purposes unfold.