Conservatives across the country are freaking out about President Obama’s claim that “people committed terrible deeds in the name of Christ” at the National Prayer Breakfast. Everyone from Rush Limbaugh and Jim Gilmore to Megyn Kelly and the hosts of Fox & Friends is venting about it. Unfortunately, the president is exactly right.

Every century in the history of Christianity is full of examples. But one of the most vivid cases of Christian-motivated bloodshed is what was happening exactly four hundred years ago, in the winter of 1615. Long-standing religious hatred and political tensions were escalating across Europe. When spiritual leaders incited violence, their followers were keen to comply. The means of killing were gruesome and imaginative. Arms were ripped from living torsos, writhing bodies stretched on racks, and men’s severed genitalia burned before their dying eyes. Kings, princes and politicians employed draconian measures to squelch criticism and halt change.

A century before that, Martin Luther’s attempt to purify Christianity of its papal poisons led to decades of struggles across Europe. More than 100,000 poorly armed farmers were slaughtered in 1524-25 when they took Luther’s teachings to imply greater social justice. Over the course of the 16th century, villages were razed, schools closed and disease left unchecked. By 1615, the continent was teaming with terrorist plots, counter-plots, and spies. But when Catholic councilors were sent to Prague and summarily tossed by the Protestant assembly out palace windows, a line was crossed. The so-called Defenestration of Prague of 1618 marks the official start of the Thirty Years’ War.

In 2015, longstanding religious hatred and political wrangling are again sweeping Europe with their own shadowy sources in the last century. Kings, princes and politicians again employ draconian measures to control criticism and stop change. In this global struggle, villages have been destroyed, schools bombed, and disease left unchecked. Nor have our contemporaries lacked imagination in their violence. Schoolgirls have been kidnapped, journalists beheaded, and interrogation methods enhanced. Our cycle of violence is much the same as that of our predecessors. Unchecked power and ignorance promote loathing, leading to increased viciousness, intolerance, and more hatred. Chérif Kouachi, one of the men responsible for the Charlie Hebdo massacre, was first moved to radicalism by images of American soldiers humiliating Muslims at Abu Ghraib prison. Brutality and stupidity beget more of the same.

People are constantly making the argumentthat Islam must contain the seeds of violence sewn by its followers. How else can we explain the violence of so many of its faithful? Sam Harris infamously claimed last year that “Islam is the motherlode of bad ideas” and has recently described sympathizers of Islam as “fake liberals” acting “in the name of political correctness.” U.S. Congressman Peter King is applauded for warning that American mosques are breeding-grounds for jihadists.

But the same logic applies to European Christians in 1615 who were willing to commit horrors in the name of their faith. The promise of heavenly salvation encouraged many. Out of concern for the wellbeing of their communities, political and religious leaders across Europe hoped to promote their version of God’s truth. The most insightful religious leaders of the sixteenth century, out of deep-seated concern for the souls of their followers, promoted the fear and anxiety that so easily bubbles over into hatred and violence. The Catholic Inquisition is infamous, but early modern Protestants were no slackers in promoting fear and hatred. Martin Luther himself was intolerant of Catholicism, increasingly vitriolic about Judaism, and eager to condemn followers who dared promote harmony among Christians. For theologians like Luther, salvation would not come to those who wavered from the narrow path.

The underlying problem here is profound. By caring so deeply about their flock, religious leaders in the period leading up to 1615 inadvertently undermined the safety of everyone. In response to those who promoted harmony with Catholics, Luther insisted, “I would rather be torn to pieces and burned a hundred times than make common cause” with anyone who would tolerate Catholics. Whether or not Luther was a hateful man is for theologians to debate, but he was the proximate cause of much of the hate that led to the difficulties of 1615. For early modern religious leaders like Luther, Calvin and all those other Christians gripped by the certainty of God’s truth, the dangers of false teachings justified intolerance. But such intolerance turned out to breed so much hatred and violence that it became virtually impossible for anyone to practice their faith. Death and disease struck all faiths with equal ferocity. Everyone lost out except politicians who carved power out of chaos.

But early modern Christianity was also the source of great social change. Its teaching about the equality of human souls under God was the mainstay of those arguing for the rights of women and against the brutality of slavery. It was used to justify slavery in one century and undermine it in another. It motivated the Ku Klux Klan to burn crosses and Freedom Riders to rise above fear’s demons. Martin Luther King Jr. found his own certainty in Christianity and used it to change the world. As Martin Luther’s namesake famously wrote, “The arc of the moral universe is long, but it bends towards justice.”

Obama’s comments about Christianity were much more reserved than they could have been. In the winter of 2015, we should not lose sight of the vast and gruesome horrors rendered in the name of the Christian God following 1615. Arrogance reigned, anxiety soared and the people of Europe died in huge bloody numbers. The source of terrorist acts in our era is not Islam any more than Christianity was the cause of the thousands upon thousands who died in the Thirty Years War. The source of such religiously motivated violence is a volatile mixture of intolerance, ignorance, fear, economic disadvantage, and political machinations. The president’s comparison between Islam and Christianity is important: any religion can be used to promote crimes against humanity.

Christia Mercer is Gustave M. Berne Professor of Philosophy at Columbia University.