This episode of "Catechism in a Year" podcast focuses on explaining the dogma of the Holy Trinity. Fr. Mike Schmitz breaks down the concept into three key points: the Trinity is one, the divine persons are distinct, and the divine persons are relative to one another. He uses quotes from various councils and theologians like St. Gregory of Nazianzus to illustrate these points, emphasizing that the Trinity is not three separate gods but one God in three persons. The episode aims to help listeners understand this complex theological concept, highlighting the importance of recognizing the distinctness and unity within the Trinity.