The mental ailment of wholly believing Christian teachings that are clearly ridiculous; such as the world is 6,000 years old, Adam and Eve started civilization, Noah had two of every animal on Earth in his Arc living in harmony, etc…
Christiansanity has been identified as the root cause of backwards religious protests and the sufferers’ need to “save” their friends by turning them to the Bible and its teachings.
Guy 1: "Yo, what's up with that chick in class who bitched out the professor for saying the world is billions of years old?"
Guy 2: "Oh you didn't know? She's suffering from Christiansanity, it's not her fault, but it is contagious so be careful."
Crazy Bitch: "The Apocolypse is coming and it's all because of people like you! REPENT! REPENT!!!!"