One God in Three Persons. The Trinity is a great mystery, but a fundamental belief of the faith. Sr. Mary Cecilia explains the difference between Who God is and What God is within the Trinity, and how this distinction accounts for our belief that God is Three Persons in One Substance.
- Online Audio: Bishop Barron’s homilies on the Trinity:
- Book: William McDonough’s The Divine Family
- Online Audio: Scott Hahn’s God’s Family and Ours: The Church and the Trinity