sign. It often carried the meaning of a military oath of obedience.1 The Greek original mysterion referred to hidden realities or sacred rites such as those found in the ancient mystery religions. Tertullian (c. 160- c. 220) was one of the first Christian authors to speak of the baptismal ritual as a sacramentum. As the church developed, many of its rites and ceremonies were called sacraments or believed to have a sacramental significance. Peter Lombard, in the early and mid-twelfth century, postulated