Religious Account (Christianity)

In mainstream Christianity the Devil is known as Satan and sometimes as Lucifer, although it has been noted that the reference in Isaiah 14:12 to Lucifer, or the Son of the Morning, is a reference to the Babylonian king. Some modern Christians consider the Devil to be an angel who along with one-third of the angelic host (the demons) rebelled against God and has consequently been conemned to the Lake of Fire. He is described as hating all humanity, or more accurately creation, opposing God, spreading lies and wreaking havoc on the souls of mankind. Other Christians consider the devil in the Bible to refer figuratively to human sin and temptation and to any human system in opposition to God.
Satan is ofter identified as the serpent who convinced Eve to eat the forbidden fruit; thus, Satan has often been depicted as a serpent.Though this identification is not present in the Adam and Eve narrative, this interpretation goes back at least as far as the time of the writing of the book of Revelation, which specifically identifies Satan as being the serpent (Rev.20:2).
In the Bible the devil is identified with "The dragon" and "the old serpent" in the Book of Revelation 12:9, 20:2 have also been identified with Satan, as have "the prince of this world" in teh Book of John 12:31;14:30; "the prince of the power of the air" also called Meririm, and "the spirit that now worketh in the children of disobedience" in the Book of Ephesians 2:2; and "the god of this world" in 2 Corinthians 4:4. He is also identified as the dragon in the Book of Revelation and the tempter of the Gospels.
Beelzebub is originally the name of a philistine god (more specifically a certain type of Ball, fom Ba'al Zebub, lit. "Lord of Flies") but is also used in the New Testament as a synonym for Satan. A corrupted version, "Belzeboub," appears in The Divine Comedy.
In other, non-mainstream, Christian beliefs the word "satan" in the Bible is not regarded as referring to a supernatural, personal being but to any 'adversary' and figuratively refers to human sin and temptation

Religious Account

Judaism
In mainstream Judaism there is no concept of the devil like in mainstream Christainity or Islam. In Hebrew, the biblical word ha-satan means "the adversary" or the obstacle,or evern "the prosecutor" (recognizing that God is viewed as the ultimate Judge).
Hebrow Apocrypha
The Apocrypha are religious writings which are not generally accepted as scripture by jdaism and many modern-day Protestant sects of Christianity. In the Book of Wisdom, the devil is represented as the one who brought death into the world.
The 2nd Book of Enoch, also called the Slavonic Book of Enoch, contains references to a Watcher Grigori called Satanael. It is a pseudepigraphic text of an uncertain date and unknown authorship. The text describes Satanael as being the prince of the Grigori who was cast out of heaven and an evil spirit who knew the difference between what was "righteous" and "sinful". A similar story is found in the book of 1 Enoch; however, in that book, the leader of the Grigori is called Semjaza.
In the apocryphal Literature, Satan rules over a host of angels. Mastems,who induced God to test Abraham through the sacrifice of Isaac, is identical with Satan in both name and nature.
For the Chasidic jews of the eighteenth century, Ha-satan was Ball Davar.
The Book of Enoch contains references to Satariel, thought also to be Sataniel and Satan'el (etymology dating back to Babylonian origins). The similar spellings mirror that of his angelic brethren Michael, Raphael, Urieland Gabriel, previous to his expulsion from Heaven.