Abraham Kuyper was raised in a nineteenth century Dutch Reformed environment deeply influenced by the Enlightenment which concentrated civic power in the state which dominanted civic life, the church included. In response, Kuyper re-articulated the power of the institutional church to address the resultant ills perceived in church, state, and society. This dissertation analyzes the power of the institutional church in Kuyper's ecclesiology through an investigation of his primary works, historical cultural context, and comparison with other theologians and philosophers of ecclesial power. For Kuyper, the institutional church is structurally grounded in creation, emerging after the Fall as an institution of human society. It occupies an essential place as a sphere with its own direct accountability to Christ, independent from other spheres. The church exists bi-modally: as institution and organism. In both modes, the church is the bearer of the salt and light of the Gospel to the world. But the institutional church does not accomplish its task with the same means or power as other cultural institutions. It is a unique sphere of public life with a unique form of power. The unique power of the institutional church emerges from Kuyper's comprehensive Calvinist worldview . The power of the institutional church is its unique vocation, in vital union with Christ, to proclaim the comprehensive Word of God (through proclaimed Word, celebrated sacraments, discipleship, and diaconal acts of justice and mercy). This proclamation is oriented toward personal and public conversion, not directly through ecclesial cultural dominance but indirectly through public Christian witness. This analysis is then brought into critical dialogue with others to highlight and clarify it for application to the church today. It is argued that Kuyper's insight has not been fully received, that it is deeply resonant with Scripture, and that it remains rich with potential for the contemporary world.