Where did you get that idea? (Web searches say this came from John Calvin, FTR.)
Have a look at the history of the being called “Heylel ben Shachar” in Isaiah 14:12-15 (translated “Lucifer qui mane oriebaris” in the Latin Vulgate). No human could ever have been the places this being has been.
I never said Lucifer or Satan were human; I said I always thought they were two separate entities. It seems there’s such a stark contrast between Satan in Job and Lucifer in Isaiah.