In this Sunday School lesson, Wayne Johnson, Provost of City Seminary of Sacramento and retired Elder of Covenant Reformed Church of Sacramento, introduces the history, purpose, and theological significance of the Heidelberg Catechism, one of the most important confessions of faith in Reformed theology. Written in 1563 under the leadership of Frederick III and primarily authored by Zacharias Ursinus and Caspar Olevianus, the Catechism emerged during the Protestant Reformation as a biblical, pastoral teaching tool to instruct believers in the Christian faith. The lesson explains how the Heidelberg Catechism was shaped by key Reformation leaders such as Martin Luther, Philip Melanchthon, and Huldrych Zwingli, combining Lutheran clarity with Reformed covenant theology. Unlike polemical confessions, the Heidelberg Catechism emphasizes Christian comfort, assurance of salvation, and belonging to Jesus Christ within the covenant community. This overview highlights the Catechism's biblical foundation, Christ-centered focus, pastoral tone, and lasting role in teaching Reformed doctrine. It also explores how the Catechism was designed to unify churches, strengthen families in biblical instruction, and provide a clear summary of the gospel rooted in Scripture. This introduction helps Christians understand why the Heidelberg Catechism remains a trusted resource for teaching, discipleship, and understanding the core beliefs of the Reformed Christian faith.