Lutheranismus is a branch of Protestant Christianity that originated from the teachings of Martin Luther, a German monk and theologian, in the 16th century. It emphasizes justification by faith alone, the authority of Scripture, and the priesthood of all believers. Luther's 95 Theses, which criticized the practices of the Catholic Church, sparked the Reformation and led to the establishment of various Lutheran churches. Lutheranism is characterized by its liturgical worship, the sacraments of Baptism and Holy Communion, and a strong focus on God's grace. It has a significant presence in countries like Germany, Sweden, and the United States, where it has shaped cultural and social life.