Although I plan to soon, I have not read Paradise Lost from start to finish. I have read some of the books in depth. Also, I have not read the Bible, although I am familiar with alot of parables within it.
None of which really answers your question.
The only recommendation I would make is the power of guided readings of 'Great Works'. I found the lecture series by Prof. John Rogers from Yale on Milton and Paradise Lost as invaluable for a first time look at the poem.
link
https://www.youtube.com/watch?v=H62G9yIN5Wk