Did all of the angels fall with Lucifer when he became a demon?

 

First off, neither is Satan a Demon, nor has he fallen from heaven yet.

Demons are an entirely different species. Demons are the deceased offspring of those angels that mated with human women long ago. Many of them were those giants mentioned in the bible and in numerous accounts of many people. God detested what the angels had done, so he bound their souls to earth, instead of letting them rest with humans after their death.

As for Lucifer, he may not have his heavenly rank anymore, hence the name “Satan” (adversary). What he has though is full dominion over this world system - he is a brilliant businessman, a clever strategist. He knows humans better than we do, on every level. His goal is to keep as many humans as possible away from Jesus Christ. He has been very successful in his efforts.

Plus, demons do help him a lot.