There is a process in which the fallen angels, demons or evil spirits must cause you to go through in order to have control over any/your soul. They must cause you to transform your whole being to what they are now. They do this with very convincing lies and deceptions at every step you make away from who you are to what they want you to become. In order to over take your entire being. This goal of theirs can from just a moment in time to the rest of your life. The closer you become to what these evil entities are. The easier it is for them to reside within you. Even if it is for just a moment or for an entire lifetime.
Fallen angels, spirits and evil entities are respecters of no one. They do not obey anyone or anything. So one of the first things that a demonically controlled/manipulated soul will begin to show is disrespect and disobedience to those whom they have not shown before. When at one time you were respectful and obedience to the various rules which governs humanity. You begin to not care/apathy so much for those rules. For many this change is gradual for a few it is immediate. For whatever reason why, I have no idea. Apathy is most likely the very fist trait which begins to appear within a human being. This is often times magnified by cigarettes, drinking as well as all forms of selected media. Which alters thinking's and perceptions of what is real.
A soil can be to acidic or the alkalinity can be to high. So a good farmer wants to keep his soil just right in order to grow the fruits or vegetables he wants. There is a process in order to achieve the perfect soil in order to maximize growth potential. This similar thinking process is the same for those fallen angels. They need for the human soul to become like they are now. In other words they need to cause and trick the human being to come down to their level/frequency. Once this is achieved the human being becomes like an open vessel in which anyone can pilot.
The natural and often times unknown human defenses in which we all have. Can become weakened to the point that a demonic entity or demonic forces can gain entry into the host body. If not from within. The host body can be used like a remote controlled (RC) car, plane, boat. In other words the human being becomes a controlled drone of the fallen angels. Doing their bidding without even being aware they are not in control over themselves. Does an RC car or a drone know who the human is which controls them? no of course not. Same thing in comparison.
I think many bad people were once good. They at some point decided not to care anymore. Then selfish desires of wanting what they could not have. Caused their apathetic being to cause harm and suffering to others in order to achieve what they wanted. Thus, their own disrespect of them and being disobedient to the laws of the land. Followed suit.
I think the fallen angels purposefully choose those humans who have great depth of passion within them. Because, they know that passionate soul will exceed in horrific deeds where others just will not have the heart for it. But, first the fallen angels must cause the passionate person to become apathetic. Then from this apathetic sate cause this passionate person to hate and become angry. Then with all of this pent up negative emotion. They cause this passionate person to release all of their hate and anger with an act of vengeance. All of this is through ongoing lies and continuous deceptions. Even though lies and deceptions which are believed to be true for many thousands of years.
Added on 31 July 2016:
The scene of a new demonically controlled person.
Like a baby all things are new to them. Can you imagine an adult acting with all manor of amazement to all of the new sensations they experience. Such as gravity and the echoes of noises. For an adult seeing a person like this will cause your spidey sense to spike. As mine does.
Like a woman who is completely amazed that their water bottle is empty. It is what happens when you spill it and drink it. For the new demonically controlled person. It is just completely a genuine feeling and true realization. Just like a toddler discovering a new thing.
Musings of an American Truck Driver