Lutheranism is a major branch of Western Christianity that identifies with the theology of Martin Luther, a German reformer. Luther's efforts to reform the theology and practice of the church launched the Protestant Reformation. Beginning with the 95 Theses, Luther's writings disseminated internationally, spreading the ideas of the Reformation beyond the ability of governmental and churchly authorities to control it.
The name "Lutheran" originated as a derogatory term used against Luther by Johann Eck during the Leipzig Debate in July 1519. Eck and other Roman Catholics followed the traditional practice of naming a heresy after its leader, thus labeling all who identified with the theology of Martin Luther as Lutherans. Martin Luther always disliked the term, preferring instead to describe the reform movement with the term "Evangelical", which was derived from euangelion, a Greek word meaning "good news", i.e. "Gospel." Lutherans themselves began to use the term in the middle of the 16th century in order to identify themselves from other groups, such as Philippists and Calvinists. In 1597, theologians in Wittenberg used the title "Lutheran" to describe their church.
The split between the Lutherans and the Roman Catholics began with the Edict of Worms in 1521, which officially excommunicated Luther and all of his followers. The divide centered over the doctrine of Justification. Lutheranism advocates a doctrine of justification "by grace alone through faith alone because of Christ alone" which went against the Roman view of "faith formed by love", or "faith and works". Unlike the Reformed Churches, Lutherans retain many of the liturgical practices and sacramental teachings of the pre-Reformation Church. Lutheran theology significantly differs from Reformed theology in Christology, the purpose of God's Law, divine grace, the concept of perseverance of the saints, and predestination.