'Don`t you know there aint no devil That`s just God when he`s drunk`
HolyGod is right, in the bible and in early Christian theology the devil (Satan, Lucifer, whatever) is basically God`s enforcer and the angel in charge of the damned. Very much part of team.
It was only much later that they combined some characteristics of pagan gods they were superceding and made him the Great Enemy. Helped `explain` the problem of evil.
`Tell me, wise priest, if God is all powerful and wholly good why is there evil?`
`Because of the big scary bogey-man who is going to get you if you keep asking questions. Also, something to do with Free Will, but we`ll get back to you on that. And women, obviously.`