What is the conceptual background of Paradise Lost in accordance with Islam?

Fundamentally, The Islamic text describes Adam and Eve's leaving paradise as an opportunity for redemption by denying the notion of Original Sin. The Christian text, on the other hand, calls the banishment of Adam and Eve as the consequence of their eating of the forbidden fruit which, it considers, an Original Sin. Milton, in Paradise Lost, also works within the Christian tradition EXCEPT that in this epic poem two interesting things happen, one of them perhaps inspite of Milton: characterization of Satan, and the humanizing of Adam and Eve. The second was intentional; the first, most probably, was not.

Milton's purpose of writing Paradise Lost was "to justify the ways of God to man." The problem with this justification is not the justification itself but how to portray God! If God is Infinite then how does a poet depict the Infinite. Further, if God is Infinite, then what conceptual form can the idea of revenge and punishment (both finite notions) be justified in Milton's poem? He overcame this dilemma by  developing the character of Michael who works as a kind of mouthpiece for not only God, but Milton himself. Over and over again in his speeches to Adam, Michael mentions the difficulty of depicting God to them, and says, that he gives form to all things in paradise primarily to make Adam understand who has no conception of the Infinite.

BUT: having wriggled himself out of this dilemma, Milton walked into another trap -- and this time he may not have been very aware of it. Trying to create Satan as God's worthy opponent, Milton, perhaps unintentionally, made him a bit too heroic -- and in a literary sense, grand -- in his opposition to God, persuading critics such as William Blake to write that "Milton was of the Devil's party without knowing it."

Undoubtedly, Milton would have disagreed.

The above controversy has a heavy bearing on the question: what was Milton's ideological position regarding the Fall of Adam and Eve, and their Original Sin.

I will try and answer that question via a discussion of Al Q'Ran regarding this same issue.

As I said above, Al Q'Ran does not accept the notion of Original Sin. Adam and Eve asks God's forgiveness and He forgives them totally. He sends them to earth, not as punishment, but as an opportunity to prove themselves worthy of being back in paradise. This is the position of Al Q'Ran.

The Bible also implies the same but the stigma of the Original Sin remains. Milton is from this tradition but he presents in his poem a far more humane, complex and touching rendition of the epic struggle between celestial quartet of God, Satan, Adam and Eve:

1. In either hand the hastening Angel caught


2. Our lingering parents, and to the eastern gate


3. Led them direct,...


4. They, looking back, all the eastern side beheld


5. Of Paradise, so late their happy seat,...


6. Some natural tears they dropt, but wiped them soon;


7. The World was all before them,...


8. with wand'ring steps and slow,


9. Through Eden took their solitary way.

Sorry, for the longish quote, but I couldn't help it. The lines highlight the typically post-New Testament spirit that Milton wanted his poem to embody. By so doing, I think, he lifted the poem right out of didactics, into the realm of poetry.