The course aims to lead to an understanding of the mystery of the Church by starting from the explanation of the epistemological foundations of ecclesiology, which allow tracing the assumptions, demands, and perspectives of the theological study of the Church in harmony with the renewal carried out by Vatican II. The mystery of the Church is analyzed along a dual path, historical-dogmatic and systematic. In the first approach, the issues related to the formation of ecclesiological models in history will be highlighted, with particular attention to the post-conciliar period. In the second approach, the themes related to the nature and mission of the Church in the world will be deepened and developed, with an opening also to the ecumenical and interreligious question. Regarding Mariology, the conciliar approach will be favored, which places the figure and role of the Virgin Mary in the life of the Church, and starting from the analysis of the eighth chapter of Lumen gentium, the various Mariological themes concerning her dogmas and systematic reflection on Mary’s role within the Son’s redemptive work, as well as Marian devotion and the Mary-Church connection, will be critically constructed.