Who do Evil Spirits Possess?
Obviously evil spirits do not just posses any body they would like or we would see a lot more examples. Right? What kind of people do they go after. Do they have to be weak spirited or already evil? Does someone have to openly invite the spirit in?
Evil spirits possess people on various levels. It depends how much people open up to them. If the person makes a habit of listening to an evil spirit, accepting their ways and desiring them, then the evil spirit can eventually take them over completely.
Evil spirits will first attempt to get a wedge in somewhere. They can use dislike of another person (for example). They can work at this to make the wedge larger. If the person accepts to be conned like this then the evil spirit can become a stronger force of evil in them.
However the evil spirit will use any weapon it can lay its hands on. It is up to you whether you accept to supply them. They will try any distortion of ideas: Lust, greed, pride, anger. They can try them all if one isn't working. They can also try them pretending to be righteous in their application - "Oh, I can't talk to that person, he's a Catholic." Or that he murdered someone. Or performed some other crime that you might find repulsive.
A person can be conned into getting a bad perspective of things within the church. A person can look down on those that seem to dirty the chapel, for example. Or looking down on those with noisy children, don't do home teaching, don't pay tithing, smoke, drink or whatever thing the evil spirit will manage to con people into being vealous for in an incorrect manner. We should not look down on such but pray for and try to assist those with problems.
If you keep your thoughts upon loving others then evil spirits can have no place in you.