Many people are aware that this year is the 500th anniversary of the Protestant Reformation. Martin Luther’s nailing of his 95 theses to the door has been taught in history classes for generations. Also well known is the role the Roman Catholic Church’s practice of selling indulgences played in Luther’s rage. What many people are unaware of, though, is how butter may have accelerated the Protestant Reformation.

[Disclaimer: I think butter is disgusting and would be ok with butter being condemned as sinful. This article is proof of my ability to be objective while writing.]

During the Middle Ages, people living in southern Europe believed that butter caused leprosy. That may not have been the official reason why the Roman Catholic Church included butter in its fast day rules (probably wasn’t), but that belief probably didn’t hurt Rome’s justification of the ban, either. Selling indulgences that absolved people of the sin of eating butter became big business in northern Europe. A monk named Martin Luther took note.

In a fascinating article published on How Stuff Works, Dave Roos explains how the butter ban affected northern Europe:

Up north in dairy-farming countries like France and Germany — where Luther lived — cutting butter from the diet was a much bigger deal. After losing meat and cheese, there was pretty much nothing left. And since fast days covered almost half the calendar year, the butter ban was akin to starvation.

The poor people in Martin Luther’s parish suffered, and Rome took advantage of that suffering to finance building projects. Luther became appalled by the indulgences, and so complained that “they sell us the right to eat foods forbidden on fast days, but they have stolen that same liberty from us with their ecclesiastical laws. Eating butter, they say, is a greater sin than to lie, blaspheme, or indulge in impurity.”

Quoting an honest-to-goodness butter historian and a professor of Lutheran history, Roos writes:

“It seems hardly a coincidence,” writes butter historian Khosova, “that most of the dairy-rich countries producing and using butter were the same nations that broke away from the Roman Catholic Church in the sixteenth century.” Professor Stjerna agrees that food-related issues — like whether a certain food was prohibited on fast days — played a major role in the frustrations that built up with the Catholic church.

More important than northern Europe’s frustrations and inconveniences caused by Rome’s butter ban, Luther saw a theological error wrapped up in Rome’s justification. In his article, Roos correctly diagnoses that:

For Luther, these clergy selling indulgences represented the larger sin of a church that convinced poor peasants that forgiveness came at a price. In Luther’s Bible-centered theology, forgiveness was free, and man would be saved or “justified” by faith and grace alone, not by following the church’s rules.

In Ephesians 2:8-9, the Apostle Paul delivers these magnificent words: “For by grace, you have been saved through faith. And this is not your own doing; it is the gift of God, not a result of works so that no one may boast.”

Martin Luther was struck by this truth. Due to his courage, the Protestant Reformation spread the Bible’s teaching that salvation is solely by grace. Less importantly, but by no means inconsequential, Luther’s actions also freed people to enjoy butter on their toast whenever they like.