Searching for a Small Opening

Ephesians 4:27 says, “Neither give place to the devil.”

If you give the devil any room of an opening he will take the entire house. Demons operate to sneak in unnoticed and quietly control and take over. This is why you cannot give the enemy any room to operate but walk with Holy Spirit and allow Him to give you discernment. Going unrecognized is what took prayer out of school and even gave leeway for witchcraft to take such a hold on certain regions.
 
In Luke 11:24-26, Jesus explains that when a demon is cast out of a person, he leaves, but he will come back and visit. If he finds it empty, swept and garnished, he will bring seven more with him. It is important that whether a person has been free from demonic possession or demonic oppression that they are filled with the Word so the enemy cannot have room in. It is why discipleship is to important after an encounter. 

When it comes demonic activity, there is a difference between demonic possession and demonic oppression. Possession is when a demon actually controls a person. In Mark 5:1-20, Jesus comes across the Maniac of Gadara who was controlled by a Legion of demons. Legion is a regime of 6000 soldiers. This man was controlled so greatly by demons that no one could bind him with chains, and he lived in the tombs. They asked Jesus not to allow them to leave the region. Spirits have access to bodies through the soulish realm, which they seek to use to control a region. This can occur through what you give the enemy access in your senses (music, movies, etc.), the wrong soul ties (sexual relationships), and the family baggage (generational curses). When they left the man they entered swine. Pigs were routinely sacrificed to Baal. They would violently run down a steep place and drown in the sea. Demons search through dry places, not deeper waters.
When the man of Gadara was delivered, he was seen sitting (in his seat of authority), clothed (with humility) and in his right mind (the mind of Christ). After this miracle happened, the people prayed for Jesus to leave their coasts, which shows how that Legion still controlled the region. 

Oppression is when Satan exercises his authority against someone. Judas Iscariot was possessed, allowing greed to become an avenue for which to be controlled and later betray Jesus Christ (John 13:27). Peter was oppressed of the devil through denying the name of Jesus, but his weeping unto the place of repentance (Matthew 26:69-75)! A Christian cannot be demonically possessed because there is no “saved demon”. He cannot cross the blood line, but you can be oppressed if you give him room to operate. Acts 10:38 says, “You know of Jesus of Nazareth, how God anointed Him with the Holy Spirit and with power, and how He went about doing good and healing all who were oppressed by the devil, for God was with Him.” There is freedom from demonic oppression in Jesus Christ, and if the Spirit of Christ rests within you, you have the authority to set those who are demonically oppressed free!