Impervious to logical reasoning.
1. Person A: Scientists have come to the conclusion that the Earth is 4.5 billion years old.
Person B: Lies, it says on the bible that God made the Earth 5,000 years ago.
Person A: Yeah, he also sent his zombie son (who happens to be his own father) to tell you to bow down, drink his blood and eat his flesh, or else you'll burn for the rest of eternity. You religious nut.
2. Tom Cruise and John Travolta are religious scientologists.