What does Mark 3:27 mean?The scribes from Jerusalem are trying to convince the people that Jesus casts out demons through the power and authority of Satan, not God. Jesus has explained how doing so would be counterproductive, since Satan would be undoing his own evil work.
The strong man is Satan, the house is his domain, and the goods are what he possesses—in this case, a blind and mute man whom Jesus releases from the power of a demon (Matthew 12:22). Jesus cannot use Satan's power to cast out the demon because He needs to bind Satan in order to free the man. He does this through the power of the Holy Spirit.
Luke's version of this account is followed by an odd story of a man who is freed from a demon (Luke 11:24–26). The demon is not destroyed, just displaced. After wandering for a time, he gathers seven other demons and they all possess the man, leaving him worse off than when he began.
The alternative to this scenario is that the man must be inhabited by another spirit—a good Spirit. This is what salvation in Christ offers. At the moment of salvation, we are indwelt by the Holy Spirit. He frees us from the oppressive sin nature and guarantees that we are God's possession. As a kind of side-effect, He also protects us from demon possession, since a demon can't dwell where the Holy Spirit is.
This is why Jesus had to ascend into heaven after the resurrection (Acts 1:6–11). As nice as it would be to meet Him personally, He is only one man. He had a hard enough time getting through all the people in Capernaum; our world now has over seven billion people who would want His time. That is why He said, "…it is to your advantage that I go away, for if I do not go away, the Helper will not come to you. But if I go, I will send him to you" (John 16:7). The Holy Spirit reaches the whole world (John 16:8), not just a tiny portion of the Middle East.
During the Millennial Kingdom, Satan will be bound (Revelation 20:2). Jesus will rule as king of Israel. Peace will come to the world, and Israel will see the Old Testament prophecies fulfilled. Like the demon-possessed man in Luke 11:24–26, however, this is temporary. At the end of the millennium, Satan will be released and one last time incite the people to rebel against God (Revelation 20:7–9). Satan will lose, once and for all, and spend eternity in the lake of fire (Revelation 20:10).