I will try and not make this sound like a sermon so please bear with me: I am a christian and have used Christianity as a game component before and think it can work well however it does require some fundamental changes in how things - and magic in particular - are viewed (things which I beleive Celebrim has addressed effectively) anyway
First a comment on the relative positions of God, Satan and Man
Satan is a fallen angel a created being and as far below God
I'd make him an Outsider (Solar works) and Epic level Scorcerer Rogue /Barbarian with an Epic Intelligence and Strength.
Satan is in fact the enemy of Man (and not God as none is powerful enough to oppose God) and throughout history he attempts to tempt and destroy 'Man'. In Geneis 3.15 (after the Fall from Eden GOD says to the serpent "
And I will put enmity between you and the woman And between your seed and her seed. He shall bruise your head And you shall bruise his heel"
Anyway Satans role is to TEMPT Man and Accuse him of wrongdoing. The reason GOD allows this is unknown but part of Gods plan.
Ultimately however it is the Son of Man (Jesus) who defeats Satan (by his Sacrifice on the Cross)
Anyway the point is Satan vs Man (not Satan vs God - and we know from Job that Satan and God talk and 'work' together - with God as referee)
Celebrim said:
I would assume that all the named spiritual beings who are not God have Divine Rank 0. These beings grant spells by direct petition, which is to say, they cast the spells not the enactor (which actually is true of god as well) when they notice someone asking them to interveen. It particularly amuses the evil enactors to make the 'spell caster' think that the power derives from themselves or that somehow they have forced the enactor to act this way.
Celebrim your discussion of this topic is wonderful and doctrinally sound (from a Christian perspective anyway) Yes God is all powerful and the ONLY diety and this quoted section is excellent
Anyway I am most impressed by your 'magic system' which is very insightful and a perfect fit with doctrine. Christian (and Jewish and Islamic imho) clerics invoke the Grace of God and it is God who causes a Miracle.
However manifestation of 'Arcane' (and modern pisonic) powers is a deception perpetrated by demons (Divine rank 0).
Your description talks of Satans using his own power to make mortals beleive they are casting spells by their own 'power'
this fits perfectly and also links back to the belief that Witches familiars were manifest demons. Using your system it is in fact the Familiar which casts spells but lets the mortal beleive that they have the power.
I am further impressed by this as it perfectly illustrates the Sin of Vanity (being the beleif that a person has their own 'power' and can do things without God) which was the major cause of Satans fall in the first place (Lucifer beleived he could be 'Like God').
Interestingly, Christianity has never claimed that 'arcane' magic is impossible, and there is even a hint that it is specifically forbid because it is possible - and horribly dangerous. Also, God considers it missing the point, because its about the acquisition of personal power and any personal power other than his own looks pretty cheap to him.
Yes this is absolutely true and magic is mentioned throughout the old testament (in 1 Samuel 28 we even see a case in which a ghost is summoned up) and yes it is extremely dangerous both because it exposes the mortal to 'Spirits' (some of whom are demonic) and because it means relying on power other than the Grace of God
Anyway hope this helps
1GOD works through miracles granted to those who have faith
2Magic is a deception perpetrated by demons (in the form of Familiars?)
3The biggest Sin a Paladin or Cleric can fall into is that of Vanity and beleiving they can do things without relying on the Grace of God.