Christians who don’t cast out demons say to me: Christians can’t have demons! They also say: The Holy Spirit prevents it.
So, how can Christians have demons? Well, every person I pray over to cast out demons believes in Jesus Christ, and has believed for months, years or even decades. We don’t even do deliverance prayers unless they believe in Jesus.
And how do demons enter Christians? It is possible to grieve the Holy Spirit through wilful sin. Sin allows demons into us whether you’re a Christian or not.
Further, the authority to cast out demons has been given to us by Jesus. If we don’t use this power or don’t know how to exercise our authority, the demons stay in.
This is the truth: If a person commits wilful sin, even if that person believes in Jesus, a spirit enters in and starts to have influence over us:
Romans 7:19-21 King James Version (KJV)
19 For the good that I would I do not: but the evil which I would not, that I do.
20 Now if I do that I would not, it is no more I that do it, but sin that dwelleth in me.
21 I find then a law, that, when I would do good, evil is present with me.
What is sin? Sin is that spiritual power seeking to enter us to take control over us. If we give in to anger, a spirit of anger enters our body so that we lose control over ourselves. So Cain killed Abel because of anger and hate:
Genesis 4:7 King James Version (KJV)
7 If thou doest well, shalt thou not be accepted? and if thou doest not well, sin lieth at the door. And unto thee shall be his desire, and thou shalt rule over him.
From Adam to the time of John the Baptist, we were at the mercy of these spiritual entities of sin which entered into our bodies through wilful disobedience. When Jesus came, he gave us the authority to expel sin, which are what we call demons, from ourselves.
Mark 1:27 King James Version (KJV)
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.
Through Jesus Christ, mankind received the power to expel sin/unclean spirits. This is the gospel of repentance and the remission of sins written of in the book of Luke:
Luke 24:46-47 King James Version (KJV)
46 And said unto them, Thus it is written, and thus it behooved Christ to suffer, and to rise from the dead the third day:
47 And that repentance and remission of sins should be preached in his name among all nations, beginning at Jerusalem.
If you are a Christian and you do not have the power to remit sins from yourself or anyone then something is very wrong. Jesus Christ is the living God and he gave us the authority over all the powers of the enemy (even death itself) so that we can use this power to set people free from the effects of sin:
John 20:23 King James Version (KJV)
23 Whose soever sins ye remit, they are remitted unto them; and whose soever sins ye retain, they are retained.