These verses were probably a word of warning to Jesus" critics who were scattering rather than gathering with Him ( Luke 11:23). [1] If Song of Solomon , they climax Jesus" argument. They warn against casting out demons, which some of these critics were evidently doing, without replacing them with something stronger, namely, the life of God that entered those who believed in Jesus (cf. John 3:16). A formerly demon-possessed person who did not believe on Jesus was in greater danger after his exorcism than he was before it. The expelled demon could return to inhabit his or her spiritually empty spirit with additional demons. [source][source][source]
These final words then carried Jesus" warning further. Not only was it bad to oppose Jesus and attribute His works to Satan, but it was worse to exercise God"s expulsive power without also preaching the gospel to people. [source][source][source]