Belief in the supernatural develops as a natural consequence of the way our brains work, so it should be no surprise that religion is both pervasive and enduring.

JAMES E. ALCOCK

This article is a modified excerpt from Chapter 16, “The God Engine,” in Belief: What It Means to Believe and Why Our Convictions Are So Compelling (Prometheus Books, 2018).

There are more than 10,000 religions in the world today, and while most involve relatively small numbers of devotees, the major ones each encompass hundreds of millions of followers. Almost nothing seems too bizarre to be incorporated into religious belief, but what may appear strange to the outsider does not seem so to the faithful. Consider:

• If you think it bizarre to abandon the bodies of deceased loved ones atop tall towers devoured by birds, then you probably were not reared as one of the world’s 2.6 million Zoroastrians.

• If you think it absurd to believe that diseases are caused not by germs, bacilli, or viruses but instead by lapses of faith, then you probably were not reared as one of the world’s 150,000 Christian Scientists.

• If you think it strange to believe that humans are the descendants of Thetans, a group of omnipotent gods, and that our emotional problems are due to “engrams” in the brain created by traumas in prior lives on another planet, then you probably were not reared as one of the world’s 500,000 Scientologists.

• If you think it weird to worship a god with the head of an elephant or in the worship of another god, Shiva, to rub clarified butter on a temple lingam that is considered by some scholars to be a stylized phallus, then you probably were not reared as one of the world’s one billion Hindus.

• If you think it curious to wave silk or paper streamers (“nusa”) over someone in a rite of purification or for new car owners to take their cars to a shrine to be prayed over and purified, then you probably were not reared as one of the world’s 2,700,000 Shintos.

• If you think it peculiar to snip away the foreskins of baby boys in the service of religious faith, then you probably were not reared as one of the world’s 14 million Jews or 1.6 billion Muslims.

• If you think it odd for priests to wear masks over their mouths to avoid breathing in and killing microorganisms, then you probably were not reared as one of the world’s 4.2 million Jains.

• If you think it inconceivable that “ancient Hebrews of America” buried golden tablets written in Egyptian in a hillside in the United States and that these were later recovered and translated with the help of an angel, then you probably were not reared as one of the world’s 15 million Mormons.

• If you think it horrifying that parents, in the name of religion, deny lifesaving blood transfusions to their dying children, then you probably were not reared as one of the world’s 7.1 million Jehovah’s Witnesses.

• If you think it shocking to celebrate one’s faith by eating the flesh and blood of one’s heavenly savior through a spiritual transformation of bread and wine (symbolical or literal depending on your sect), then you probably were not reared as one of the world’s 2.2 billion Christians.

Whatever its form, religion is powerful and pervasive and, for billions of people, obviously important. Yet, while major religions such as Islam, Christianity, Hinduism, and Buddhism have endured since ancient times, others, despite having enjoyed great appeal for centuries, have disappeared into the history books. No longer does anyone worship Zeus, the supreme god of the ancient Greeks; Marduk, the Babylonian god of creation; Bast, the Egyptian goddess of protection; Jupiter, the supreme god of the Romans; the Incan Apocatequil; or the Aztec Huehueteotl. Those bygone gods were central figures in highly developed theocracies and were as real to their devotees as are today’s deities to contemporary worshippers.