First-Edition Copy of Protestant Reformer Martin Luther's 'On the Freedom of a Christian' Found In French Library

May 27, 2015 11:54 AM EDT

A first edition of Protestant Reformer Martin Luther's On the Freedom of a Christian, including handwritten notes for a second edition, has been discovered in a library in northern France.

According to a report from the BBC and French news sources, American researcher James Hirstein, a Latin linguist at the University of Strasbourg, discovered the book while preparing for a conference on Reformation-era humanism at the Humanist Library in Selestat, France.

Hirstein reportedly told the BBC that the book represented a "missing link" in Luther research because it provides "important insight" into the reformer's thinking at the time and allows scholars to "really take into account his wishes for a definitive edition."

Martin Luther, the Catholic priest and German monk known as the father of the Protestant Reformation, is believed to have published On the Freedom of a Christian in 1520. The book was the third of Luther's major reforming treatises released that year, appearing after his Address to the Christian Nobility of the German Nation (August 1520) and the work Prelude on the Babylonian Captivity of the Church.

On the Freedom of a Christian is considered to be one of the most important works of the Reformation, as it promotes the concept that as fully forgiven children of God, Christians are free from the need for penance and other Catholic practices. Luther also further develops the concept of justification by faith alone in the book, famously writing, "A Christian is a perfectly free lord of all, subject to none. A Christian is a perfectly dutiful servant of all, subject to all."

The Christian Examiner notes that the work, which was originally written in Latin and eventually translated into German, was immediately popular among the well-educated who were beginning to question the authority and doctrine of the 16th-century Roman Catholic church.

At the time, Luther dedicated his book to Pope Leo X, whom the reformer addressed as a "lamb amidst the wolves" and "a Daniel among the lions" of the Roman church. However, Leo rejected the work and added it to the charges against the German monk, which eventually led to Luther's excommunication from the Roman Catholic Church.

French news source Fait-Religieux reports that the book discovered in the library contains almost 50 notations in red from Luther's own hand, which were a "print template" for a second edition.

The book with Luther's changes in red ink will not be viewed publicly until it can be treated with nitrogen to kill insects that had infested the book, a curator at the library has said.