In all my dealings I have come to the conclusion that the answer is summed up in this scripture:
James 4
6But he giveth more grace. Wherefore he saith, God resisteth the proud, but giveth grace unto the humble.
7Submit yourselves therefore to God. Resist the devil, and he will flee from you.
8Draw nigh to God, and he will draw nigh to you. Cleanse your hands, ye sinners; and purify your hearts, ye double minded.
If the devil is the biggest bad, then all his imps and captains are less of a threat. They all flee, as one trying to save its own existence in this realm, from those who have truly submitted to the LORD, Yahweh, trusting in the name of Yahshua Ha Meshyiach / Jesus Christ for their salvation and authority in the spirit realm.
The issue in this day and age is seemingly to first recognize their existence and presence. This is established by their contrary suggestions and statements presented to the human mind, contrary to the scriptures, the Word of the LORD, Yahweh. They prefer to attack a believer in Yahshua Ha Meshyiach covertly so as not to be recognized. One must remember that fear is the devil's chief weapon and the basis for fear is lack of knowledge and belief in the Word of the LORD. Faith in the Word of God is how we recognize and cast down every evil vain imagination that exalts itself against the Truth.
The Bible is a huge book with no reference to fear the devil. We are only to fear in reverence the LORD who will judge sin as worthy of punishment in whomever it is found not erased by the cleansing blood of the Lamb of God, Yahshua Ha Meshyiach / Jesus Christ.
The devil is a liar and the author of them. The demons are his agents assigned to steal, kill, and destroy through lies.
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There are many ways to get rid of satan and demons, but I used to have a problem similar to what sounds like yours. Here are a few tips:
1. Stop believing that a drive for evil exists. I'm not saying that you have to go off la-di-da-di-da, like your drunk, but try to understand that people make these bad choices, not a being like satan.
2. If you feel some force trying to get those voices inside your head to say things you don't want, like, 'Be evil', reconfront them with something positive, like, 'I love god. God is good.' or 'I like myself for who I am'. Try to construct some sort of rythm. (It actually works, sometimes I fall asleep doing this.)
3. Talk to a spiritualist or some kind of religious person, they may be able to help you. You can anonymously call a prayer chain, too, and they will pray for you to be successful.
Hope this helps! The alternative answer
I think the best way to deal with demons would be to stop believing in them. I mean the concept of demons existing in a world with a omnipotent god of love dosen't seem to fit. I mean (just thinking logically here) couldn't He just condemn them to hell, or smite them? In my experience, demons are just coincidental bad events and by just saying to yourself: hang on a minute... What am I seriously thinking? you can go a long way.
I was in your same position for the past few weeks wondering if its all real but no matter what. I have come from my research in demonology the alternate way to stop a a** hole like that is to simply believe in a higher power then them and simply no where they belong. There simply has to be a balance on this earth between evil and good. Some say that it is christ that will save you and allow you to banish them to condemned hell if you please but who knows those terds keep getting out then. If you wanna know some research i say you look in resourceful places like the bible or demonology books. hope i helped