Satan
In theology, the devil is Satan [Hebrew, (= (adversary]. Judaism, Christianity, and Islam all agree,the principle of evil conceived as a person; also called the Devil.
In Christian tradition Satan was the leader of the angels who rebelled against God and who were cast out of heaven.
He and his followers are seen as tempters of humanity and the source of evil in the world.
He has numerous other names, such as Lucifer,
Beelzebub, Evil One, and Prince of Darkness.
The Bible says that Satan will be thrown into a lake of fire after he loses his final battle.
Definitions courtesy The Concise Columbia Encyclopedia