In our English translations of the Bible, the word demon is commonly used when the Greek actually has 3 different words for the same word we use simply as 'demon'. For example, the KJV translates daimonion as devil when there is only one devil and not many. Obviously, the word demon is more appropriate. You could say there are many demons but only one devil.
Keeping the above in mind, there is another confused rendering from the Greek into Engish that confuses the issue when it comes to whether or not a Christian can 'have a demon.'
The verb in Greek that is used to reference a person with a demon is daimonizo which does not mean possessed. It means simply demonized. So, it is accurate to state that a person is under daimonizo or 'subject to demonic influence'...which is a far cry from possession, which word means or dictates 'ownership.'
It is simple to conclude that Christian cannot be possessed but inaccurate to state a Christian cannot be influenced to demonic influence.
There is no basis in the Greek to conclude that the word possession is intended.
I don't believe the title 'deliverance minister' is a biblical one. The Bible records no such office, like it does pastor, elder or teacher or other gift.
Why is that? Casting out demons, or driving out demons or expelling demons, is the realm of every believer and not 'specialists' whose calling is dealing with demons in people.
In Luke 10, the 72 who were sent out by Jesus came back to Him and reported that even the demons were subject to them and had to obey them...as they did Jesus. Jesus told them not to rejoice at this, but to rejoice that there names were written down in heaven; the point here for this explanation is that all 72 indicated they had success with authority over the evil spirits...there were no specialists.
Ephesians 6 describes the battle Christians have as a spiritual war and not one agains flesh and blood.
For we do not wrestle against flesh and blood, but against the rulers, against the authorities, against the cosmic powers over this present darkness, against the spiritual forces of evil in the heavenly places. v 12
Obviously I'm not going to discuss every reference in scripture with regards to demons and believers, but there is a huge difference between possession and being afflicted. Paul had a demonic affliction...the Bible records that a messenger from the devil buffeted him...Because of the surpassing greatness of the revelations, for this reason, to keep me from exalting myself, there was given me a thorn in the flesh, a messenger of Satan to torment me-- to keep me from exalting myself! II Cor 12:7
There is no doubt that God does allow demonic activity in a believer's life...Job, Paul, King Saul, Peter and others...this can come about through sin or even God's permission...however a Christian for the most part should deal with the influences of demons in their life.
Many Christians will claim that a believer cannot have any type of demonic influence and state that the Holy Spirit and a demon cannot be in the same place or space.
The Bible does not state that anywhere, but remembering that the word possession is not the word used in the original Greek, it is a mute point to state that a believer cannot be possessed.
The only way to be rid of a demonic presence is in the name of Jesus...no special ceremony or holy water or crosses etc
The truth of the victory already won for believers over the devil is the only reason the demons must leave. It's not a power a struggle. It is a matter of standing on the truth of the Bible and our position in Christ only, that assures us victory.