This work begins by providing a comprehensive account of the model of human holiness developed by the theologian Hans Urs von Balthasar. In so doing, the book also provides a detailed explication of his Christocentric philosophical anthropology. Part two argues that von Balthasar anticipates some key developments in late 20th-century Anglo-American analytical philosophy, and that certain of these developments - in particular, the "internal realism" of Hilary Putnam - provide powerful support for von Balthasar's theological philosophy. The final part elucidates von Balthasar's core intuition that human holiness is of immense apologetic value for religious faith, and concludes with a new, "internalist" theory of religious pluralism. The book should prove useful reading in upper-level undergraduate and postgraduate courses in both subjects.