If Satan does not cast out demons (Matt. 12: 25–27), why do we read in Matt. 7: 21–23 of those who, though lost, appear to have done this very thing?
The NT records several attempts at casting out demons from possessed persons. Not all were successful. In Acts 19: 13–16 two of the seven sons of Sceva, unbelievers, who tried to copy the Apostle Paul using the name of Jesus, failed miserably, only bringing the wrath of the possessed person upon themselves. Even the twelve disciples, who as heralds of the Kingdom, had been given power over demons for that particular mission (Matt. 10: 1–8), on one occasion could not cast out a certain demon (Matt. 17: 21). This was never true of the Lord. Indeed the fact that all demons were always subject to Him was a clear demonstration that the Kingdom of God was here (Luke 11: 20)––that is, in His presence all were brought to own divine authority.
In Matt. 12: 22–37, the Lord heals a man “possessed by a demon, blind and dumb”. The Pharisees, unable to deny the miracle, attribute it to “Beelzebub, prince of demons”. In response, the Lord dismisses this charge by saying that “Every kingdom divided against itself is brought to desolation, and every city or house divided against itself will not subsist. And if Satan casts out Satan, he is divided against himself; how then shall his kingdom subsist? And if I cast out demons by Beelzebub, your sons, by whom do they cast [them] out?” From this answer it is clear that firstly, the power that casts out demons is not Satanic and secondly that the ‘sons’ (disciples) of the Pharisees claimed to cast out demons––a claim that the Lord does not question.
In Matt. 7: 21–23 the conditions for entrance into the kingdom of the heavens are clearly stated. “Not every one who says to me, Lord, Lord, shall enter into the kingdom of the heavens, but he that does the will of my Father who is in the heavens” (v21). Many will say “Lord, Lord”, and hence appear to own His authority, but fail to do “the will of my Father who is in the heavens”. In that day such will protest saying “Lord, Lord, have we not prophesied through thy name, and through thy name cast out demons, and through thy name done many words of power?” (v22). Hence they claim two things: Firstly to own His authority––“Lord, Lord”, and secondly, to have performed miracles in His name––“through thy name”.
In His reply, the Lord does not deny that they had prophesied, cast out demons or performed many works of power––all in His name. What He does deny, however, is their claim that they were subject to His authority. Firstly, He says “I never knew you”. This clearly shows that they were lost, that they were not His, for "My sheep hear my voice, and I know them” (John 10: 27), and “[The] Lord knows those that are his” (2 Tim. 2: 19). Yet it is also clear that they had performed miracles in His name. Are we to conclude then that there are persons who have never known the Lord and yet who have done miracles in His name? Yes! Notice carefully the second part of the Lord’s reply. “Depart from me, workers of lawlessness”. They are not addressed as liars or deceivers, (for they had really done those works of power) but as workers of lawlessness. They had not owned divine authority––they were lawless and thus their works, marvellous in themselves, were works of lawlessness. They may have cast out demons, but they had not done the will of the Father.
The Bible records an actual example of this very thing: a man who had cast out demons and had performed miracles in the Lord’s name and yet was lost. Indeed the Bible calls him the son of perdition. His name is Judas Iscariot. The twelve disciples in Matt. 10: 1–8 are listed in pairs, the last pair being Simon the Cananaean and Judas the Iscariote. These twelve were given “power over unclean spirits” (v1) and sent out to preach and perform miracles including casting out demons (v8). Mark 6: 7 tells us that they were sent out in pairs. Judas was lost, but he was given the same power as the rest and there is nothing to indicate that he failed to exercise that power.
God can use whom He will––a Balaam or even a Judas, without the one used necessarily owning His authority. Men today may claim to do this, that and the other. Their claims may be true or false. Without questioning their claims, what they do does not prove that they belong to Christ. When the seventy returned from a mission and rejoiced at the demons being subject to them, the Lord tells them not to do so but rather “rejoice that your names are written in the heavens” (Luke 10: 17–20).