Lutheranism is a branch of Protestant Christianity that follows the teachings of Martin Luther, a German theologian and religious reformer who lived in the 16th century. Its core beliefs are centered on the idea that salvation can only be achieved through faith in Jesus Christ alone, and not through good works or other means. Lutherans also believe in the infallibility of the Bible as the ultimate source of religious authority, and the importance of the sacraments of baptism and communion. The denomination places a strong emphasis on the personal relationship between the believer and God, and typically adheres to a liturgical style of worship. Lutheran churches are found throughout the world, and the denomination has over 70 million members globally.