During WWII, isolated islands full of aboriginal people were suddenly inundated with civilization far advanced from anything they'd ever seen. To them, it was magic from the gods. After the soldiers left, the islanders built bamboo planes and control towers and cleared makeshift runways and talked nonsense into coconut headsets. They marched around with fake guns, all in the belief that these rites would summon the planes carrying the cargo back to the islands. These religions still exist today.
This is scary. We as a "civilized" culture were physically able to watch (cause?) the birth of a religion, born from phenomena the locals weren't capable of understanding, but was in no way magical. You have to wonder ... Talking into a coconut to bring the magic cargo planes back is positively absurd to us... But really, is talking out loud to an empty sky and invoking the name of god or Christ to bring an end to suffering, sickness, war, etc. any different?
http://www.damninteresting.com/john-frum-and-the-cargo-cults/