Even though Reformed Epistemology has flourished among many theistic philosophers, it is not without criticism. One of the major avenues of criticism deals with the Problem of Religious Pluralism. Plantinga's main contention in his work Warranted Christian Belief is to establish that Christian belief is rational, warranted, and justified to the Christian believer. Religious Pluralism considers the existence of two or more religions with mutually exclusive truth claims to be equally valid. This study asserts that the Argument from Religious Pluralism continues to produce a viable defeater against Plantinga's Warranted Christian Belief. Through the examination of Plantinga's Warranted Christian Belief and a comparative analysis of Zen Buddhism, we show that an extension of Plantinga's argumentation can be shown to produce Warranted Zen Buddhist Belief, where Zen Buddhism, is considered 'properly basic' for the Zen Buddhist believer, producing a defeater for warranted Christian belief that may not be defeated.