As the story goes God created Lucifer good, but he rebelled because of pride and fell, became evil - the accuser
One of my favorite books is Paradise Lost. I had parts of it memorized before I even picked up a Bible. Most peoples views on Lucifer are Milton's rather than Biblical. It has been a very popular book for centuries.
Farewell Happy Fields
Where Joy for ever dwells: Hail horrors, hail
Infernal world, and thou profoundest Hell
Receive thy new Possessor: One who brings
A mind not to be changed by Place or Time.
The mind is its own place, and in it self
Can make a Heav'n of Hell, a Hell of Heav'n.
What matter where, if I be still the same,
And what I should be, all but less then he
Whom Thunder hath made greater? Here at least
We shall be free; the Almighty hath not built
Here for his envy, will not drive us hence:
Here we may reign secure, and in my choice
To reign is worth ambition though in Hell:
Better to reign in Hell, then serve in Heav'n.