By ancient religions, demons were thought of as ancient deities or nature spirits.

In Mesopotamia, the ancient Assyrians and Babylonians believed demons were of two kinds. The first ones lurked in places that were dangerous for humans to tread. Some of this type, such as the Sedu and Lamassu were both evil and protective spirits. The second type were the Etimmu, ghosts of people who died by misfortune. They were greatly feared. Disease and mischance were attributed to demons, especially to the Etimmu.

Greeks believed daemons were tutelary spirits, they taught humans lessons, as well as protective guardian spirits. Demons taught man there are consequences to their behavior. They were considered beings somewhere between gods and humans, neither good nor bad.

During the time of Alexander the Great, Greek geography began to broaden and people moved farther apart. Alienation set in as people no longer knew their neighbors and new cultures were absorbed into the Empire. People began turning to diviners and magic users to calm their anxieties. Due to their depressive feelings of isolation, they began to believe that the earth had been created by the demiurge, dark daemons that were not welcomed in heaven.

As Christianity spread, they found that it was easier to convert other belief systems if they incorporated the pagan beliefs into Christianity. All of the good gods/goddesses became angels and the evil/controversial gods/goddesses were shoved underground as demons. The word demon became to denote evil when it was introduced to the Roman and Hellenistic worlds. Originally, Christianity claimed that stern, righteous angels stood guard over the souls of the damned and tormented them for eternity. Once paganism became absorbed, demons and angels switched roles. Demons became the tormentors and angels the protectors and teachers.

Although Judaism doesn’t officially recognize demons, they are quite prevalent in Jewish folklore, as shedim. It was believed by their Israelite neighbors that the demons race existed long before humankind and grew so arrogant that humans were formed to replace them.

In India, demons were the winged siblings to the angels and able to change at will. They are free agents, able to choose between being good or evil. They have super-human powers, but are more prone to be destructive. Included in this type are the Asuras, Danavas, Daityas and Raksasas. Others, the Bhuta, are always evil. These are formed of human souls that die violent deaths or lived wicked lives.

For Buddhists, demons are merely obstacles to Enlightenment.

The Noble Qur’aan of Islam states that jinn/ginn/djinn (genie) inhabit the ethereal realm, the immaterial would between the physical and divine and are generally good spirits. As stated by Prophet Muhammad (blessing and peace of Allah be upon him), narrated by his wife ‘Aa’eshah: “The angels were created from light and the Jinn from a fiery wind” (Sahih Muslim English trans., vol. 4p. 1540, no. 7134) The Noble Qur’aan also adds that if a demon hears the word of Allah and believes, it can be saved.