In this book, Karly Poyner-Smith approaches the ExVangelical movement from the perspective of a purity discourse scholar to examine purity as a discourse in religious and non-religious spaces of contemporary culture.
American evangelicalism and its sub movements remain a considerably large component of Western culture and politicism. American evangelicalism's religious doctrine's usage of purity focuses on race, gender, sexuality, disability, and nationalism, which in turn forces ExVangelicals to extract themselves from the discourse of purity they grew up learning and subscribing to. Poyner-smith contemplates this notion by weaving together various ExVangelical narratives including interviews, diaries, and memoirs. In doing so, she argues that we may come to understand post-evangelicalism as not merely a movement away from evangelical places, but as a complex rhetorical movement in which individuals collectively create new spaces designated for their critique of evangelicalism, thus creating a rhetoric of impurities.

Additionally, Poyner-Smith provides examples of how readers can take the ExVangelical example of a rhetoric of impurities and apply it to non-religious spaces that the target audience most likely interacts within daily, including healthism, feminism, the college classroom, and heteronormativity. Ultimately, the author conducts a rhetorical analysis of this movement, allowing readers to further understand purity's influence in everyday rhetoric beyond the religious and historical field.