Demons are not just earth bound spirits.

There are dimensions “higher” than our physical reality and dimensions considerably lower. If angels exist, why not demons?
Every religious culture in the world has accepted the existence of evil spirits of one sort or another. All religions and spiritual beliefs have had Shamans,Priests and Healers for dealing with these demonic forces and entities. If we don’t hear about something we will not fear it. We may then never encounter it. Die hard sceptics rarely experience anything that they would consider as paranormal.
There are many people who are experiencing negative spiritual phenomena. They need and often cannot find anyone to help them combat this.
These are the categories of highly negative spirits, demonic forces and energies that I have experienced.

Highly negative self created energies.

For example if a person is constantly creating negative energies such as depression, anger, jealousy and many other negative emotions and feelings. These create negative energies and energy cannot be destroyed. Although it can be changed into something more positive. However this negative energy, if it is constantly produced can take on a life of it’s own. Which will then begin to control the person who has created it.
There is also highly negative sent energy. This is normally sent by another person with negative intent. e.g. in the case of a curse.
There are also entities / demonic forces created for a specific purpose by the head of a cult, a Priest, during the Black Mass / devil worship. These Priests, Shamans or head’s of cults can also create a demonic force to be sent to inflict damage, both physical and emotional on another person.

Demonic Spirits

There is a hierarchy of demons who can come from many sources. e.g. fallen angels, created demonic forces and the equivalents in terms of names from most other religions e.g. Archangel Lucifer.

Demons can appear in whatever form they wish to, enabling the creation of fear or to mislead. I have experienced demonic forces who have appeared as energy, a young man, a woman, a classical devil figure. They are also very adept at liying in order to mislead or gain the trust of a person so that the person will give away their free will. Once free will has been taken the demonic force can either possess or force the person to carry out acts against their will. Or even damage their health both mentally and physically.

Demons can cause both physical and mental illness depending upon the protection of the person. Their willingness consciously or subconsciously to give away their free will. The person’s or state also affects the strength of demonic attack. The more spiritually enlightened you are the more likely you are to come under psychic attack. The more enlightened you become the more of a threat you become to the dark side. (The brighter your light, the more it attracts the darkness).