The Pharisees seeing Jesus cast out demons said that he was doing this by the power of the devil. Jesus used this as an opportunity to teach the people the truth of where his power came from.
Jesus asked the Pharisees, “How can Satan cast out Satan?” He also said to them that a kingdom or a house that is divided against itself cannot stand but will come to an end. In history we see divided kingdoms always fall. Today we see the same in some countries and businesses. When the leadership is divided the whole country or business suffers as they are pulled in two directions and they fall. And if Satan rises up against his own evil kingdom, then his kingdom will not stand.
Jesus then said that you cannot plunder the house of a strong person unless you first bind the strong person. A strong person naturally will defend their property and, being strong, will often prevail in their defence. However if they are bound they will not be able to put up a defence and then their house can be plundered. Jesus had the power and authority to bind the evil spirits and cast them out. In every case we see that the demons recognised him and feared him for they cried out as he commanded them to come out of the people and be gone.
It is the purpose of Satan to bind man and bring man under his evil power and the power of sin. Jesus offers man freedom from sin and release from the bondages of Satan and of this world. Through Jesus we have the strength of a stronger on to bind the realm of Satan and thus plunder his kingdom.
Satan’s kingdom will fall, but not because he is divided against himself. It will fall because there is a stronger one who has overcome the kingdom of Satan, and that stronger one is Jesus Christ.
After Jesus had thus shown that it was not by the power of Satan that he cast out demons, he showed the evil of their statement. Jesus said that all sins would be forgiven mankind, even if they were to utter blasphemies. However he said that anyone who blasphemes against the Holy Spirit will never be forgiven. Blasphemy against the Holy Spirit is the unforgivable sin and anyone doing so will be guilty of an eternal sin.
Why is this so? A man could blaspheme Jesus or God and be forgiven but to blaspheme the Holy Spirit is an unpardonable sin. When we consider who the Holy Spirit is we can perhaps understand why the Lord took such a harsh stand on this matter. The Holy Spirit dwells within man on this earth for the purpose of transforming man into the image of Christ.
The Holy Spirit has possibly the worst of jobs because he is living in the kingdom of Satan and subjected to all the sin, evil and unholiness of this world. He is living with the filth of man to try and change man. Within each person he will have to put up with the failures each person makes and the setbacks that occur as they try to walk in the ways of God. He will have to put up our weaknesses, failures, faults, disobedience and faithlessness as he performs his task.
For the Holy Spirit who has been sent by God to do this task it must be a rotten job. To have to put up with the evil of this world day in and day out when he could be in the heavenly places with God and Jesus, it must be a terribly difficult task and cause one who is holy great anguish. It is my opinion, and only an opinion, that it is for this reason that blasphemy of the Holy Spirit is the only sin that will not be forgiven. To have to put up with the filth of this world and then to be called evil is too great a burden and thus unforgivable.