The volume commemorates the life and work of Fr. Joseph Mueller, S.J., former Dean of the Jesuit School of Theology at Santa Clara University and a Catholic theologian specializing in patristic exegesis, ecclesiology, and ecumenism. This tribute brings together contributions spanning a broad range of theological disciplines, including biblical, historical, and systematic theology, with a particular focus on ecclesiology. Several essays in the volume aim to reflect Fr. Mueller’s scholarly interests, as initially articulated in his doctoral dissertation on the use of the Old Testament in the ecclesiology of the Church Fathers. The memorial volume thus closely follows Fr. Mueller’s academic journey, showcasing the breadth and depth of his influence on theological scholarship.