Beelzebub in the context of "Horned deity"

In Christianity, the Devil, also known as Satan, is a malevolent entity that deceives and tempts humans. Frequently viewed as the personification of evil, he is traditionally held to have rebelled against God in an attempt to become equal to God himself. He is said to be a fallen angel, who was expelled from Heaven at the beginning of time, before God created the material world, and is in constant opposition to God. The Devil is identified with several other figures in the Bible including Lucifer, Satan, the serpent in the Garden of Eden, the tempter of the Gospels, Leviathan, Beelzebub, and the dragon in the Book of Revelation.

Early scholars discussed the role of the Devil. Scholars influenced by neoplatonic cosmology, like Origen and Pseudo-Dionysius, portrayed the Devil as representing deficiency and emptiness, the entity most remote from the divine. According to Augustine of Hippo, the realm of the Devil is not nothingness, but an inferior realm standing in opposition to God. The standard medieval depiction of the Devil goes back to Gregory the Great. He integrated the Devil, as the first creation of God, into the Christian angelic hierarchy as the highest of the angels (either a cherub or a seraph) who fell far, into the depths of hell, and became the leader of demons.

A devil is the mythical personification of evil as it is conceived in various cultures and religious traditions. It is seen as the objectification of a hostile and destructive force. Jeffrey Burton Russell states that the different conceptions of the devil can be summed up as 1) a principle of evil independent from God, 2) an aspect of God, 3) a created being turning evil (a fallen angel) or 4) a symbol of human evil.

Each tradition, culture, and religion with a devil in its mythos offers a different lens on manifestations of evil. The history of these perspectives intertwines with theology, mythology, psychiatry, art, and literature, developing independently within each of the traditions. It occurs historically in many contexts and cultures, and is given many different names—Satan (Judaism), Lucifer (Christianity), Beelzebub (Judeo-Christian), Mephistopheles (German), Iblis (Islam)—and attributes: it is portrayed as blue, black, or red; it is portrayed as having horns on its head, and without horns, and so on.