Who wrote "The Freedom of a Christian"?

This text, more properly called "On The Freedom of a Christian"—and sometimes termed "A Treatise on Christian Liberty"—was written by Martin Luther in 1520. It was the third text he had produced that year, which was significantly written in both German—his native language and the language of the people—and Latin. This is related to Luther's conviction that the Bible needed to be made accessible to the people, rather than be kept mysterious and remote by being intoned in Latin only during mass. Luther is very focused in this treatise on the idea that faith is its own justification. Instead of adhering rigidly to the law of God and striving to achieve God's forgiveness through the performance of good works, a sinner who puts his faith in God will be redeemed through this. In putting forward this thesis, Luther was making a claim very distinct from the belief of the Catholic Church, which was wedded to the concept of "good works" alongside the sale of indulgences as a means of attaining heaven.