As I've mentioned before I am not a demonologist, not do I want to be. Though the spirit world is highly intriguing, the side-effects of getting involved with spirits can be terrifying at their worst. I don't have a step-by-step guide to getting rid of demons, but enough people have asked that I think it's only appropriate to try to answer.
While I may not be able to tell you how to force a demon out of your life, there are a handful of simple tricks you can use to ward off all kinds of malicious spirits and regain control of your life. I'll tell you what I know and hopefully it will help.
The first thing to understand about demons and other spirits is that they don't truly exist in our plane of existence. That is, they do not have a corporeal, earthly form. We, on the other hand, do. This is a key advantage for humans.
As you may have noticed from demonic stories, demons don't get to wander free at full force in our world. If they did they would have destroyed and corrupted everything by now. Instead, they only have temporary power that can be used here - unless they find a way to gather more.
Think of it like swimming. We can dive down into the water and hold our breath for some time. While we're there we can make a mess of things, or simply see what's going on. After a short while, though, we run out of oxygen and need to come back to "our world" on the surface. This appears to be the same with demons. They can "hold their breath" and come into our world for a time, but they can't stay for too long.
The exception comes in a
similar way as swimming. Just as a diver can go for longer dives with a
breathing apparatus, so can a demon take longer stays on our plane of
existence if they have a way of doing so.
So what is the "oxygen" that demons need to stay longer? The answer is energy. Spiritual energy is by far the strongest, though spirits have been known to drain batteries, heat, and light among other sources. Energy is energy in a sense, but comparing spiritual energy to electricity is like comparing a nuclear reactor to a car battery. Both can power a light bulb with ease, but they're still not in the same ballpark in terms of strength and range.
To put it simply, demons feed off of energy. Now, just as electricity is polarized (positive or negative), so is all energy. This is exactly what people are referring to when they talk about positive and negative attitudes. We largely ignore these types of personal or spiritual energies because they can't be measured very well on a scientific scale. All that means is that we don't have the technology or understanding needed to measure them, not that they don't exist. If you don't believe me, try getting a dog to listen to you. Smart dog owners know that you don't have to say a word, you just have to change your energy and your dog will pick up on it much better than if you are yelling commands.
The key to keeping demons from affecting you is to learn how to control your energy. Evil spirits need negative energy while positive spirits need positive energy. It's just like a battery - it doesn't work backwards. By starving a demon of negative energy you are effectively suffocating it from this world, just like a diver with no oxygen. No matter what techniques you use to do this, the key is to remember that removing negative energy is the engine that makes it work.