Luther taught that salvation is not earned by good deeds but received only as a free gift of God's grace through faith in Jesus as redeemer from sin. His theology challenged the authority of the pope of the Roman Catholic Church by teaching that the Bible is the only source of divinely revealed knowledge and opposed sacerdotalism by considering all baptized Christians to be a holy priesthood. Those who identify with Luther's teachings are called Lutherans.
His translation of the Bible into the language of the people (instead of Latin)
made it more accessible, causing a tremendous impact on the church and
on German culture. It fostered the development of a standard version of
the German language, added several principles to the art of translation, and influenced the translation into English of the King James Bible. His hymns influenced the development of singing in churches. His marriage to Katharina von Bora set a model for the practice of clerical marriage, allowing Protestant priests to marry.
In his later years, Luther became strongly Antisemitic,
writing that Jewish homes should be destroyed, their synagogues burned,
money confiscated and liberty curtailed. These statements have made
Luther a controversial figure among many historians and religious
scholars.