Matthew 12:45
Then it goes and brings with it seven other spirits more evil than itself, and they enter and dwell there, and the last state of that person is worse than the first. So also will it be with this evil generation. The seven more evil spirits communicate the escalation of the spiritual danger when the empty house is reoccupied. The application to the evil generation communicates that Israel's generation that underwent John's reformation but rejected Jesus is in precisely this condition: partially cleansed but not filled, and therefore vulnerable to worse occupation than before.