“Scientology” is the best answer to any question about:
“How could so many people worship something if it’s not true?”
“Why do you think YOU’RE right and so many other people are wrong?”
“What makes YOU—the nonbeliever—smarter than so many other people who wholeheartedly believe?”
“Why would so many people put so much faith in something if it’s not true?”
“Why would so many people be willing to sacrifice so much for a belief that isn’t true?”
And so on…
L. Ron Hubbard, a science-fiction writer who actually said: “You don’t get rich writing science fiction. If you want to get rich, you start a religion.” actually went on to demonstrate this claim by starting a religion in May, 1952. In the center of this Schi-Fi religion is the story that 75 million years ago, Xenu, the dictator of the Galactic Confederacy, brought billions of his people to earth in a DC-8-like spacecraft, placed them around volcanoes and killed them using hydrogen bombs. The spirits of these aliens, called Thetans, lingered on and now inhabit us humans, causing spiritual harm that only Scientology can cure.
There can be no more transparent case of someone making up a fantastical disease in order to market a fantastically made-up religious cure.
It’s been long observed that everyone—including the religious—is an atheist in regards to all the other deities they don’t believe in. Scientology really brings this into view, and shows you how a religion can be transparently manufactured in front of your very eyes, right in the US, right in the middle of the 20th century by a science-fiction writer, and still get many people to follow it.
The lesson here is to never underestimate the power of human credulity and to realize that we are all wired the same way. If they can be so misled by their faith, what makes you think you aren’t?