Four centuries before the Holocaust, a major Protestant church reformer savagely attacked "this damned, rejected race of Jews" and urged his followers to burn their synagogues, demolish their homes and force them to do manual labor.
Martin Luther, the religious pioneer who helped to launch the entire Protestant movement, published two long anti-Jewish attacks in 1543, one of which was so obscene that it offended even some of his staunchest supporters.
This tragic secret is about to be publicly exposed and denounced by an unexpected source -- the leaders of the 5.2 million-member Evangelical Lutheran Church in America, the nation's largest Lutheran denomination.
"The irony is that the vast majority of Lutherans in this country today do not even know about these writings by Luther," said Massachusetts Lutheran Bishop Robert Isaksen. "But the various hate groups of this century, including the Nazis, did know about these writings, and they used them to try to justify some very ugly things."
At a church-wide meeting in Missouri last month, Bishop Isaksen persuaded other leaders in his denomination that they should delve into the past and repudiate this chapter in Luther's life. Their official statement of rejection is expected to be issued by early next year.
"This would be extremely important for Jewish-Christian relations," said Rabbi A. James Rudin, the national inter-religious affairs director for the American Jewish Committee.
"We have to see the church's final text," said Rabbi Rudin, who has been discussing drafts of the statement with church leaders. "But this would be a very important building block for us if they forthrightly speak out against . . . these very, very vicious anti-Jewish polemics by their church's founder."
For many Christians, the effort is a surprising new chapter in the gradual movement since World War II to improve Jewish-Christian relations.
The Roman Catholic Church, the world's largest Christian denomination, formally recognized Judaism as a valid faith in the 1960s and has been trying to repent for its own historic contributions to anti-Semitism. Similarly, Lutheran-Jewish relations have been slowly improving over many years.
This new repudiation of Luther's essays is likely to send countless church members flipping back through the pages of history.
Historians are puzzled by the sharp transformation in Luther's writings about Judaism.
Luther lived from 1483 to 1546, an era when anti-Jewish attacks were sweeping across Europe. During his lifetime, Jews were forcibly expelled from parts of what are now Germany, Spain, Poland, Italy, Portugal and other countries.
Early in his career, Luther surprised other Christian leaders by urging them to stop these persecutions. He hoped that Jews would respond to his kindness by converting to Christianity.
"From a Jewish perspective, it is discouraging that Luther started out saying some rather positive things about Jews but by the end of his life he became very frustrated that Jews did not convert," Rabbi Rudin said.
That is one common explanation of Luther's change of tactics: He was angry that his conversion strategy did not work.
Another theory stresses that he was a sick old man by 60, an advanced age in the 16th century. He suffered from ulcers and other painful disorders. That may have left him so bitter that he fell back into the more common anti-Semitic attitudes of his day.
Luther wrote, in part: "For it is as easy to convert a Jew as to convert the Devil. A Jew and a Jewish heart are hard as wood, as stone, as iron, as the Devil himself. In short, they are children of the Devil, condemned to the flames of hell."
His hateful slurs grew so bitter that, at one point, he even offended some of his followers by suggesting that Jewish people drank urine.
"When people today actually read what Luther wrote, they are really just horrified," Bishop Isaksen said. "These were very terrible things that he wrote."
In the 16th century, the essays were copied and widely circulated, especially in Lutheran circles, fueling the anti-Semitism in what is now Germany.