The Trinity is one of the most essential doctrines of the Christian faith as it reveals a magnificent truth about God—that he is one God eternally existing as three distinct persons. While Christians often struggle to find the right words to describe the union of Father, Son, and Spirit, the Bible gives clarity concerning the triune God’s activity in nature (creation), grace (redemption), and glory (reward). In the second installment of the Short Studies in Systematic Theology series, theologian Scott Swain examines the Trinity, presenting its biblical foundations, systematic–theological structure, and practical relevance for the church today.