John F Kennedy Jr. had it all. His Dad had the top job, he was born into great wealth, power, and influence. He had the good looks, intelligence, and image that made him the world's most eligible bachelor (until his misfortune of getting married).
One fateful day, he flew his plane with his wife and sister-in-law on board and crashed upside-down into the ocean, all occupants perished. Investigations concluded that JFK Jr. suffered a condition known as "spatial disorientation".
In other words, he was temporarily in a state of delusion.
Delusion: an idiosyncratic belief or impression maintained despite being contradicted by reality or rational argument, typically as a symptom of mental disorder.
He thought that he was flying the plane safely and all was ok but in fact, he was flying upside down and plummeting towards the ocean.
We may all suffer from delusions from time to time for one reason or another, however, isn't it different when religious believers maintain their deluded beliefs constantly and permanently?