God may well have written that script as well and Lucifer had no choice in the matter to become the evil one---
nor do we have any choice...it is all pre-determined. In which case I have no reason to try and convert atheists nor do any churches have any need to exist.
Its Gods play.
So now we have a fully predetermined universe.
Assuming we have no choice whether to serve (or acknowledge God) or not, does it matter to you personally what you do?
It matters insofar if the Scriptures are cogent, coherent, and free from internal inconsistencies. If you set out to show that we have freewill, then how do you reconcile instances where there is clearly no freewill offered to some people?
Did the Pharaoh have freewill? If god hardened his heart, then God is directly responsible for Pharaoh's condition. If God controlled him like a puppet, then he did not have freewill.
And then of course there is the illusion of freewill when there is none to speak of, for God's own omniscience makes it an impossibility.
Let's use a card game as an analogy. If you know the outcome of a "choice" (choice used very loosely here) then there really is no choice at all, only the illusion of it to those not in on the scam. The other players think they have a choice, but the deck is loaded by the dealer in a predetermined way. So it is with god in the scriptures.
If Lucifer only exists to be the bad guy, then did he have a choice or is he simply playing the role he was assigned? Obviously the latter.
Therefore there cannot be freewill where there is an omniscient God.
"Reason obeys itself; and ignorance submits to whatever is dictated to it" -- Thomas Paine