Cyrill of Alexandria
Due to their disbelief in Christ and their rejection of the Savior, the unclean spirit once more assailed them. It discovered their hearts vacant and lacking reverence for God, and, as if it had seized control, it resided within them. Just as the Holy Spirit takes residence within a heart that is free from impurity and clean, so too does the unclean spirit make its home in the lives of the unrighteous. As I have noted, they are devoid of all goodness and have no reverence for God.
The Jewish people contemplated such ideas regarding Christ when He elucidated: When an unclean spirit departs from a person, it roams through desolate places in search of rest. Finding none, it declares, I will return to my home from which I departed; and upon returning, it discovers it cleaned and in order. Then it proceeds to bring seven other spirits more malevolent than itself, and when they enter, they take residence there, making the final state of that individual worse than the initial (Luke 11:24-26). Having been in bondage in Egypt, they lived a life filled with various forms of defilement, with an evil spirit residing within them, for such spirits inhabit the hearts of the unrighteous.
Read more (71 words)
By God's grace, they were liberated by Moses and were given the law for guidance, which called them to the light of true knowledge of God, leading to the expulsion of the foul spirit. However, because they did not accept Christ and turned away from the Savior, that unclean spirit returned. It finds their hearts vacant, lacking the fear of God, and it comes in to dwell within them once more.