This essay was rejected by almost every mainstream U.S. magazine. In a nation of believers, it's extremely difficult to express skepticism in mainstream media. That's sufficient proof for billions of people. Most of humanity prays to invisible spirits and envisions mystical realms.
Most politicians invoke the deities.
Supernaturalism pervades our species, consuming billions of person-hours and trillions of dollars. Millions of prayers to unseen beings are uttered every hour, and millions of rituals performed. This extravaganza requires a vast array of priests and facilities. The cost is astronomical. Every last shred of it.