Most Christians don’t really consider themselves superstitious. Only 14 percent of Protestants and 15 percent of Catholics think there’s something unlucky about the number 13, and only 20 percent of Protestants and 27 percent of Catholics think knocking on wood keeps bad luck at bay. That’s not surprising, since most American Christians don’t see superstition as squaring with their idea of the Bible. But it is a little ironic, since these superstitions, and many others, got their start in Christian tradition.
Friday the 13th’s unlucky reputation started because Judas was the 13th guest at the Last Supper, and Jesus died on a Friday. Other cultures outside of Christianity have also held that the number 13 is unlucky (in Norse mythology, it’s associated with Loki) but the Christian spin on it popularized the idea. Without 18th century Christians drawing a line between the number 13 and Judas, it’s very unlikely that the number would have the reputation it does today.
Historically, Christians saw the line between the spirit world and our own physical one as much flimsier than we do today. Angels and demons were considered part of their lives, and were used to explain both natural phenomena and misfortune. This helped give rise to many superstitions, which blended with Christian teaching in a way that is still with us today. Here are a few other common superstitions that got their start in Christianity.
Crossing Your Fingers
In Ancient Rome, early Christians crossed their fingers as a secret signal to each other. After Christianity became legal and, eventually, the dominant religion in much of Europe, the shape of the cross was later thought to be protection from evil. Having an actual cross was best, but crossed fingers would do in a pinch.
Walking Under a Ladder
Ancient tradition used to hold that a ladder rested against the cross Jesus was crucified on, and you can see evidence in a lot of ancient art. That belief intertwined with ancient Egyptian beliefs about the triangle as a symbol of the divine, so walking through a triangle fractured the lines and invited misfortune.
Knock on Wood
The origins of knocking on wood to stave off evil are a little mysterious, but it’s clear that the superstition has been around for a long time. One common theory is that knocking on wood started out as touching a crucifix (usually wooden) when making a vow. Over time, touching became knocking and crucifix became any wood within reach.
Saying “God bless you” to a sneeze
There was a time when it was believed that the air expelled from your body when you sneeze left room for evil spirits to invade and set up shop. That’s a pretty distressing thought under the best circumstances, and the Black Plague was decidedly not the best circumstances. As one way of combating the Plague, Pope Gregory the Great ordered everyone within earshot of a sneeze to say “God bless you.” It’s unclear how well that worked, but the practice stuck.