Humans are concerned with boundaries which makes them different from other animate beings, and their community (thus their world) is different from other communities (other worlds).
The view of the cosmos has influenced us to understand what is told - the angels and demons.
Cosmos are viewed as monistic at Hinduism, where the cosmos are wholly sacred or participate in a single divine principle (Absolute or Brahman).
Cosmos are viewed as dualistic in Gnosticism (the esoteric religious dualistic belief in a Christian heretical movement, that flourished in the Greco-Roman world of 1st and 2nd centuries CE).
The world of matter was considered as evil and the realm of the spirit known the good.
The third view of the cosmos is found in the monotheistic religions of Christianity, Judaism, Zoroastrianism, and Islam, which centres on a tripartite universe: terrestrial, celestial and sub-terrestrial.
The third view influenced the Western concepts of angels and demons with scientific and metaphysical concepts.
Related on the views of a tripartite cosmos
Biblically Hellenistic (Greco-Roman cultural), and Islamic worlds of thought that the terrestrial realm was a world where humans are limited by the factors of space and time.
The celestial realm is composed of seven spheres dominated by the seven planets, which serve the realm of the divine and the spiritual.
The sub-terrestrial realm is the area of the spiritual powers of darkness.
The highest level is the ultimate of the sacred. For instance, Yahweh, the God of Judaism, whose name is holy should not be spoken.
Bythos, the unknown beginning of the heavenly Father of Christianity, known through the divine Word, or reason, Jesus Christ and Allah, the almighty, and the God of Islam.
To reveal the purpose and destiny of humans, the highest beings of the terrestrial and celestial sphere enabled humans to know who they are, what could be their origin, and what is their destiny through celestial messengers known - the angels.
The message is focused on the identity of the source of the revelation. Angels attempt to pervert the message of the celestial being to confuse humans' understanding of their present boundary situation.
The terrestrial beings or destiny are supra-terrestrial beings malevolent in function, although not demons. Including such malevolent angels are the Devil of Christianity and in Judaism the Iblis (the Devil) of Islam, taking the form of a serpent from the biblical story of the Eden Garden.
Based on the later interpretations of a story, it disrupt humanity's understanding of the creature's boundaries and their limitations.
It tempted Eve and Adam to eat the fruit from the tree of knowledge to know good and evil so they might become like God (the divine beings of heavenly court).
According to Zoroastrianism, the Evil Spirit (the Angra Mainyu, later Ahriman) attempts the subservient spirits like the Lie, Evil Mind and Pride to deceive the terrestrial humans so they choose a destiny of sub-terrestrial— the punishment in a chasm of fire.
After the 16th-century of Copernican revolution (the theories of Polish astronomer Copernicus), where humanity's view of the cosmos got radically altered, the earth no longer was seen as the centre of the cosmos but was seen as a planet of a solar system with a small part of a galaxy of an infinite universe, the concept of demons and angels was no longer seen appropriate. Tripartite cosmos—heaven being above, earth in the middle, and hell below—appeared the anachronism.
Freudian "myth" of human personality and the other psychological studies initiated a new dimension based on the study of angels and demons.
Medieval iconography graphically depicted angels and demons being the hybrid creatures that often defied the most vivid imaginations of the persons who view them, which was supplanted by psychoanalytical, psychological, and modern mythological symbolism coupled along with theological reflection.
Dualistic cosmos ~
Religious traditions viewed the cosmos in a dualistic fashion like Gnosticism, angels believed to be celestial beings controlling certain spheres, where a soul passes to free itself from the shackles of the material existence.
The knowledge of angels and their names served as a needed prerequisite to achieve an eventual union with the ultimate spiritual reality.
Seven angels rule the seven planetary spheres are
Adonai (Lord), Gabriel, Ariel (lion of God), and other angels.
Angel of creation of the world of matter, Yahweh (known the Demiurge, or Creator) was evil from the gnostic view because the Creator tried to keep spiritual persons from knowing their destiny, true origin and nature.
A dualistic religion Manichaeism was founded in the 3rd century CE by an Iranian prophet very similar to Gnosticism that divided the world into two spheres like Goodness (the light) and Evil (the darkness).
The principles were mixed in the world of matter, and the salvation was to unmix the material and the spiritual so one may achieve a state of absolute goodness.
Are demons common in all mythological views?
Demons have a lengthy historical role and a wide geographical as the spiritual beings influencing humans in their relationship to the holy. They are non-human, semi-human, nonhuman and ghostly beings, who attempt humans to not attain their higher spiritual aspirations or to perform activities needed for their normal living and their well-being.
During the 17th-century in Europe, several demons were catalogued using their powers to entice people into indulging their desires or basic instincts.
The nightmare demons were formed from the semen of copulation, and demons deceive people into believing they can perform transvections (the alleged rites of witchcraft).
During the 20th century (the early Christian polemicists), alleged demons were noted by prevailing religions of the world being the former gods or spiritual beings who overpowered the doctrinal views of conquering people.
Hence the Celtic, the Teutonic, Slavic, or Roman gods were reduced to demonic antagonists of Christ, his angels, and his saints absorbed the cults of Christian saint figures.
The followers of the ancients were no longer influential deities and were subjected to persecution as the advocates of witchcraft, particularly in Christian Europe.
Angels and Demons ~
Angels and demons are categorised as malevolent, benevolent, ambivalent or neutral beings mediating between the sacred and profane realms.
The benevolent beings ~
Benevolent beings, are angels also the ghost of ancestors or spiritual beings placated through rituals or sacrifices. They assist humans to achieve rapport with God.
Angels are revealers of divine truth and are efficacious to help people attain salvation or special favours. Their function is to praise, serve and do the will of God. Angels intervene in human affairs to reward the faithful, save the weak, punish the unjust and destroy the wicked.
Intertestamental book on Tobit (hidden book- not accepted by Protestants and Jews), Archangel Raphael helps Tobias, son of Tobit on a journey revealing magic formulas for curing his father's blindness and counteract the demon power of Asmodeus.
Angels are participants in creation and serve as the providential continuance of the cosmos. The Clement of Alexandria influencing Hellenistic cosmology function as the movers of stars to control the elements of air, earth, fire and water.
Angels are guardians of individuals and nations. Guardian angels watching over children has been a belief of Roman Catholics. Angels are conductors of the souls of the dead to the supra-terrestrial world.
Seraphim and cherubim, the two superior orders of angels are the winged creatures guarding the throne of God.
The Malevolent beings ~
Malevolent beings are fallen angels, ghosts, demons, goblins, hybrid creatures, evil spirits, and the narakas (creatures in hell). These creatures hinder humans in achieving the spiritual realm, in human life also not to maintain a proper relationship with God.
Few angels are fallen from the position of proximity to God like Lucifer due to pride and for his attempts to usurp Supreme Being's position. They attempt humans to not gain a right relationship with God and provoke them to sin.
Fallen angels are agents of disease, famine, earthquakes, war, accidental deaths and several emotional and mental disorders. Persons with mental diseases are considered as "demon-possessed".
Neutral or Ambivalent beings~
Neutral or ambivalent beings divide the inhabitants of the cosmos in opposition to Supreme Being.
The legend describes jinn created out of fire some 2,000 years before the creation of the first human, Adam. Jinn has invisibility and visibility, a Jini may assume several forms like human or animal, they either help or hinder humans. Jinni uses a superior use of intellect or magic so people can manipulate jinni for their benefit.
Minor spirits like the spirits of fire, water and mountains are neutral. To keep them beneficial to humans, proper rituals and sacrifices are to be performed.