This scripture Luke 11:24-26, is talking about demon possession, and although not common in Western lands, it is well know about in places like Africa.
This reminds me of the account of Demonic influence in Act 5:1-10, of a first century Christian who must have been born again with some of the gifts of the spirit, and yet the account tells us, Satan was able to influence him. So having the holy spirit does not necessarily protect you. It has to do will free-will, God will protect you as long as you stay loyal to him. But in the case of this man, Ananias he clearly opened himself up to the influence of Satan.
So to keep ourselves protected from Satan and his demons influence, which can be very subtle, we need to keep the door shut on his influence on us, unlike Ananias.
Notice, Satan was able to influence him by the most common failing in man, pride and greed. Demon possession may be rare, but Demon influence, I think is rampant. If you allow yourself to come under Demonic influence, you could be in danger of Demonic possession!!!
