We know that the devil has kept the unsaved captive by deceving them into thinking they're on the right path when they're on the wrong path.{Through false religions,etc.}Of course, he also tries to put wrong thoughts in Christians heads,if they temporarily "turn away."But we also know that the devil does know the Sciptures,based on when he confronted Jesus after fasting for 40 days and praying. The devil, although twisting the Scriptures to suit his purposes,apparently does know them, because he quotes them .Yet if he has spiritual insight{including knowing the prophecies of the last days."Woe to the Earth and to the sea, for the devil has come down to you, having great anger, KNOWING HE HAS A SHORT AMOUNT OF TIME".}Ok, but knowing these things , he still tries to deceive those he knows can't be deceived.Like, if he knows Scripture, doesn't he realize, for example, that Jesus would continue on to the Cross for our salvation?Yet he tried to convince Jesus to sin so He couldn't be spotless and save us.....which raises the the question, if he's not doing it out of ignorance of Scripture, does he , in fact, besides deceiving others, actually deceive himself also?Seems so.