"Now when the unclean spirit goes out of a man, it passes through waterless places seeking rest, and does not find it.
Then it says, I'll go back to my house that I came from.' And returning, it finds the house vacant, swept, and put in order.
off it goes and brings with it seven other spirits more evil than
itself, and they enter and settle down there. As a result, that man's
last condition is worse than the first. That's how it will also be with
this evil generation."
I have experienced this to a degree myself back in the day . . . and have observed up close in others. It is a dreadful development. Especially now, where it seems that evil spirits are running amok, with abandon, finding open doors aplenty and invitations everywhere . . . I think it can hardly be stressed enough the dire importance to stay vigilant and protected from invading dark entities.
Christians are not carte blanch immune from such attacks and infiltration and, in fact, are the primary targets.
Also churches and families. . . . Too many pastors and parishioners are foolishly and lazily unaware of the organized, dedicated efforts of the dark side forces who work full time, with agents on the ground, to disrupt, demoralize, scandalize, divide gatherings of believers. Pride is also a factor as many also falsely believe they are too "spiritual" . . . too "smart" . . . too "above it" to be tricked by the stealthy infiltrators.
On the personal level what I have seen is this. I've known people who, by their own power, so-to-speak, have cleaned up their lives and "gotten their act together" . . . and have ceased acting in overtly sinful, "unclean" ways . . . who then later are plunged back into the old behavior, only much worse.
There is no doubt in my mind, and according to scripture and experience, that we are talking about demonic, "unclean" and "familiar" spirits who once had a great hold on someone, then that someone "cleans up their act" . . . only to have a much more serious and sinister returning of the evil spirits.
As the verse describes, they sweep their house clean--it's as if the evil influences are swept away or leave--but later they return and in greater numbers. In context, Jesus was addressing the hypocritical church/religious leaders of the day. In general, He was pointing out that when a person uses their own power and is not truly relying on the Holy Spirit, but is using by default Evil Spirit to get their house in order . . . it is bound to fail and the condition will be ie., seven times worse.
This is a big problem with false converts--those who've convinced themselves they have submitted to the Truth--to Christ--but yet have demonic strongholds hidden within which they manage to never quite touch or expel. Again, a subtle self-sufficiency and spiritual pride blinds them to the fact that they have really NOT "gotten their act together" but have merely bought a moment of breathing space and temporary respite from the invaders.
Likewise in a lot of congregations there is often a false sense of security, led by a subtly self-deceived and prideful pastor that "MY 'house' . . . MY congregation is safe, impervious to the wiles of the Wicked One." They do not study the matter, however, and are woefully ignorant to the degrees and efforts the enemies conspire by to infiltrate, disrupt, divide and destroy.
"My people are destroyed for lack of knowledge." --Hosea 4:6
Indeed, there are covens of witches, warlocks and demons virtually surrounding every church--the occult has exploded and its practitioners are legion. They actually do plan, plot and organize . . . and send in agents who masquerade as Believers . . . who will, like Soviet spies often did, lay low for long periods of time, blending in, pretending and getting involved with the church administration or small groups etc., . . . all to get close and deceive and then will start sowing the seeds of contention and chaos and scandal--many times never themselves being caught or realized. After the destruction, they move on to the next target. They expertly come off as sincere "born-again" believers and an evil thrill by the successful deception.
Real, deep and ongoing humility and severe cleaving to the truth in all things, in submission to the guidance of the Holy Spirit and the Word are primary means to avoid being duped and destroyed by these cunning, stealthy dark side operatives, whether they come in human form or in the "airs". . . .