Recent critiques of Protestantism argue that its theological principles undercut ecclesial unity while creating endless interpretive plurality. This plurality, in turn, perpetuates the secular conditions that characterize the contemporary Western world: the nurturing of personal autonomy, a buffered self that deafens theological dimensions of existence, and an unenduring institutional visibility that renders Protestant churches incapable of engaging the modern world with a unified theological voice. In this context, this article retrieves Herman Bavinck's understanding that a specifically Protestant view of the church can properly ground a catholicity that centers on a unity-in-diversity that is "confessional, international, and cosmopolitan" in character. Recent critiques of Protestantism argue that its theological principles undercut ecclesial unity while creating endless interpretive plurality. This plurality, in turn, perpetuates the secular conditions that characterize the contemporary Western world: the nurturing of personal autonomy, a buffered self that deafens theological dimensions of existence, and an unenduring institutional visibility that renders Protestant churches incapable of engaging the modern world with a unified theological voice. In this context, this article retrieves Herman Bavinck's understanding that a specifically Protestant view of the church can properly ground a catholicity that centers on a unity-in-diversity that is "confessional, international, and cosmopolitan" in character.