Lucifer and his friends couldnt take the Badass routine of eternal servitude, The Alpha Male, was putting on them. So, they just decided to give up and retire from eternal servitude to become pornstars and rulers(im serious).
Angels had it all- immortality and 100% noble life, but they broke mentally and gave It up for pussy. The perfect beings of faith deserted their position.
According to bible demons surly know of God, the problem is that they dont care about him.
The problem with the majority of population is that they dont care about God even if they believe in one.