This lecture presents a foundational exploration of Reformed Baptist doctrine by tracing the historical roots of the Protestant Reformation, emphasizing the recovery of key theological principles such as justification by faith alone, Scripture alone, grace alone, Christ alone, and the glory of God alone. It contrasts the Reformation's biblical understanding of human depravity, divine sovereignty, and the necessity of God's grace in salvation, contrasted against the Roman Catholic Church's emphasis on human cooperation, free will, and the authority of tradition. The sermon underscores the centrality of Scripture as the ultimate authority, the necessity of liberty of conscience, and the regulative principle of worship, arguing that true worship must be ordered by God's Word rather than human tradition or preference. It also highlights the enduring significance of covenantal theology, the moral law, and the perseverance of the saints, positioning these doctrines as essential to the Reformed Baptist identity and spiritual heritage.