Martin Luther (November 10, 1483 – February 18, 1546) was a German monk, theologian, and church reformer. He is also considered to be the founder of Protestantism. Luther's theology challenged the authority of the papacy by emphasizing the Bible as the sole source of religious authority and all baptized Christians as a general priesthood. According to Luther, salvation was attainable only by faith in Jesus as the messiah, a faith unmediated by the church. These ideas helped to inspire the Protestant Reformation and changed the course of Western civilization.