Today, it is not popular nor considered intellectual to believe in the devil. However, even Antonin Scalia, the late Justice of the Supreme Court, believed in the devil. Scalia was a devout Catholic and an intellectual’s intellectual who always defended his faith against intellectual elitism.
One day Scalia baited an incredulous New York Magazine reporter with talk about Satan. “I even believe in the Devil,” he said. “Of course! Yeah, he’s a real person. Hey, c’mon, that’s standard Catholic doctrine!”
I agree with Scalia. Belief in the devil and his demons is standard dogma for Protestants as well. Ephesians 6 and Daniel 10 point to an invisible spiritual war happening all around us. Even Jesus believed in the devil and spoke often of him.