Radical religious tendency whose credo consists of absolute faith in, and obedience to The Leader. Movementarians are taught that The Leader invented all of our useful modern contrivances, such as the light bulb. They look forward to the day when The Leader will take them in a flying saucer to a paradise planet.
Movementarianism largely died out when it was revealed to the flock that The Leader's flying saucer was actually a cheap, pedal-powered fake, laden with sacks of cash.
Oh, and all this happened on The Simpsons, by the way.