There's a small bit in the letter of James in chapter 2 which reads:
You believe that there is one God. Good! Even the demons believe that — and shudder.
Now this got me thinking about these entities which for the most part we can not see. What the heck do they believe? What do they know that may be of some use? They obviously believe in one God, as stated above but what else.
Part of the answer may be found in the gospel of Matthew. We're told somewhere in chapter 8 (I can't remember at the moment) that there was this man who was possessed by demons (as opposed to being repossessed which is when they can't make their mortgage repayments) and Jesus shows up and drives them into a herd of pigs who decide to drown themselves.
They actually call Jesus the Son of God; further to that they also submit to his authority. Also, they make mention that they fear being tortured before "the time appointed". So then, here we have a group of beings who: Believe that God exists; believe that Jesus is the Son of God; believe that they're under his authority and that ultimately they will be judged by him. The story is repeated in Mark 5 (probably) and we're told there that when the man saw Jesus he fell down and worshipped him.
Now for the crunch - even if you happen to know all of the Gospel and believe that it's true, it is still possible for it to mean precisely nought. Knowing a bunch of facts without doing anything with them is pointless. I know that Queen Beatrix is the Queen of the Netherlands, that she became Queen in 1980, but that still doesn't in any way shape or form even make the slightest bit Dutch.