Satan

Satan (from the Hebrew "ha-satan", "accuser") was a member of the divine council who rebelled against God and was cast from Heaven to reign over Hell, where he leads a host of fallen angels (or demons).

Satan's goal is to lead people away from the love of God, by tempting or tricking them. The only sources of supernatural power in the world are from either God (good) or Satan (evil).

Satan, in the Book of Job, is used by God to test the faith of Job (who reamined true to God through hardships). 

Satan is able to possess and control living humans on Earth, although priests are able to exorcise his influence.

Satan, is also called by several different names (deceiver, Bealzebub, Lucifer, et al). The notion of Sata, or an evil force, is noted in many if not all of the major world religions.

In the New Testament, Satan tries to tempt Jesus in the desert, and fails. --Billwsu 23:30, 7 March 2007 (EST)