The Trinity is one of the most essential doctrines of the Christian faith. The eternal God existing as three distinct persons--Father, Son, and Spirit--can be difficult to comprehend. While Christians often struggle to find the right words to describe this union, the Bible gives clarity concerning the triune God's being and activity in nature (creation), grace (redemption), and glory (reward). In this concise volume, theologian Scott Swain examines the doctrine of the Trinity, presenting its biblical foundations, systematic-theological structure, and practical relevance for the church today.