Four years of theology classes are a graduation requirement for all Cathedral students. Courses in Sacred Scripture, Christology, Paschal Mystery, morality, ecclesiology, sacraments, social justice, and ecumenism complete the theology curriculum. The basic tenets of the Catholic faith explained in theology class are frequently inserted into discussions in literature, history, current affairs, and biology.
All students are required to enroll in a religion course each semester:
- 9th Grade: The Bible: The Living Word of God and Jesus Christ: God's Love Made Visible. Designed to give students appreciation of the Sacred Scriptures as well as knowledge that will help them know Jesus Christ more personally. They will also explore the traditions of the Congregation of the Holy Cross and explore the core values which are the cornerstone of a Cathedral High School education.
- 10th Grade: Your Life in Christ: Foundations of Catholic Morality and Jesus Christ: Source of Our Salvation. Helps students understand all God has done for us through his son, Jesus Christ. They also learn that it is only through Christ they can fully live out God's plan for their lives.
- 11th Grade: The Sacraments: Encounters With Christ. Students come to understand that in and through the church they encounter the living Jesus Christ; that the Church and its sacraments (particularly the Eucharist) are the living body of Christ today.
- 12th Grade: Catholic Social Teaching: Christian Life in Society. Introduces students to the Church's social teachings as well as how the Catholic Church relates to nonCatholic Christians and other world religions.