You realize this particular form of satanism (denying all and sundry objective truths, because God is truth) is a form of satanic rebellion that even the devils can't achieve?
Only man can blind himself to truth like that. The devils are metaphysically incapable of being that stupid. They must be impressed and somewhat mystified at what they've inspired some men to do and become.
The devil is a liar and the father of lies -- but he doesn't truly believe any of them himself.
Angelic intellects -- fallen or not -- immediately see and understand (intellege) the essence of something. Much more efficient than ratiocination (step by step REASON, which is how human intelligence works). They immediately see all the conclusions and consequences, how everything goes together. There is no need to step by step reason ANYTHING for the angels and devils.
It's the difference between travelling on foot/horse/car vs. being able to BEAM anywhere like in Star Trek. Yes, both have freedom of movement. But WOW what a difference in style! One is instantaneous, the other takes hours, days, or even weeks depending on the destination.