This essay will demonstrate how Otto Semmelroth’s preconciliar work on the Church as sacrament connects with several ecclesiological themes that would later be developed in Lumen Gentium. These themes include the importance of a lay-inclusive Church, the universal call to holiness, the relationship between Mary and the Church, a Trinitarian ecclesial spirituality, and the use of sacrament as a fundamental category for organizing and interpreting a variety of images and concepts of the Church.'

First will come an attempt to take the measure of Semmelroth’s significant impact on Lumen Gentium within the context of the myriad contributions made by a large number of theologians. His first book, Urbild der Kirche, will then be examined for how it anticipates his later work on the Church as sacrament, particularly as connected with a conceptual quest for a lay-inclusive Church. This will be followed by a study of Die Kirche als Ursakrament, his work that had the most direct impact on the ecclesiology of Vatican II. Then a brief consideration of Semmelroth’s later preconciliar works will show how his focus on the personal-experiential dimensions of the Church became linked with the development of a sacramental ontology.