In the canon law of the Catholic Church, excommunication is a form of censure. In the formal sense of the term, excommunication includes being barred not only from the sacraments but also from the fellowship of Christian baptism. The principal and severest censure, excommunication presupposes guilt; and being the most serious penalty that the Catholic Church can inflict, it supposes a grave offense. The excommunicated person is considered by Catholic ecclesiastical authority as an exile from the Church, for a time at least.

Martin Luther was a German priest, theologian, author, hymnwriter, professor, and Augustinian friar. Luther was the seminal figure of the Protestant Reformation, and his theological beliefs form the basis of Lutheranism. He is regarded as one of the most influential figures in Western and Christian history.