Beresford begins his book by describing an image of Saint Bartholomew that hangs in the Great Hall in Durham Castle. The painting is an effective starting point for his analysis because in it, one can see the major themes he successfully carries through the entire book. Beresford examines many images to show the development of the cult and legacy of Bartholomew in medieval and early modern Iberia. The central theme of the book is how selfness was created through the cult of this saint. Identity construction, on the individual, devotional, social, and political levels, is at the heart of the book, and because the saint was flayed, skin is seen as a platform for the transmission of identity, as races and religions came together in the region during this period.

Chapter 1 traces the literary traditions that defined who Saint Bartholomew was in the minds of medieval and early modern Christians, particularly in Iberia. The conclusion of Beresford's analysis is that an incredibly unstable and contradictory legend emerges from the texts. In other words, the figure of the saint is malleable. This adaptability provides a conduit for the book's themes of identity and selfness, for which the skin of the saint is the locus. In chapter 2, Beresford shifts from literary to artistic depictions of Bartholomew, with a focus on images that feature his infancy. Here the author asserts that the complex ways in which artists depicted the saint's early life offer valuable insight into the way his identity entered into and shaped Iberian consciousness. Beresford argues that the images of Bartholomew as a changeling allude to anxiety over otherness, while the juxtaposition of the saint's youth with his martyrdom allows the viewer to raise larger questions about identity, holiness, and self-knowledge.

Chapter 3 examines images that show Bartholomew's threefold ministry. Beresford distills the saint's evangelical activities to exorcism, shattering of the idols, and the sacrament of baptism, which each resonated in a different way with the viewer. In the representations, Bartholomew is an unfinished product and a spiritual wanderer, like the viewer. The end result was that devotional, social, and national identity in Iberia were shaped by the images of the evangelical ministry of Bartholomew. The distinctions between what Catholicism is and what it is not, as well as the distinction between races in Iberia, are further developed and crystallized in the representations of Bartholomew's martyrdom, which Beresford takes up in chapter 4. The self-other relationship takes prominence as the saint is tortured, flayed, and killed. Beresford argues that at the sight of the cycle of the martyrdom, the mixed emotions of empathy, disgust, excitement, and morbid fascination trigger anxiety and nervous self-doubt in the viewer and further the process of the creation of self-identity. The saint's removed skin becomes a canvas for identity and a text in and of itself, attesting to the holiness of Bartholomew, which influenced the way Iberian Christians saw themselves and others in their midst.

The book's themes are carried forward into the seventeenth century and beyond in chapter 5. The book concludes with a comment on how the evolution of the images of the saint reach a culminating point in which the artistic representation can be seen as a product of the confrontation between races and religions in Iberia in the medieval and early modern periods. In the end, skin, identity, and selfness are linked in the imaginations of those who looked upon Bartholomew. One would be remiss not to mention the production value of the book itself. Reference to the beautifully reproduced artistic representations and their convenient location in the text adds to the clarity of the argument and to the reading experience.

Sacred Skin adds much to our understanding of the legacy of Saint Bartholomew. The idea that skin can transmit identity, selfness, and otherness to the observer of artistic pieces has the potential to move the field forward. Furthermore, although the book is focused on Iberia and on one saint in particular, the analytic and theoretical tools that Beresford employs could very much be extended to other holy figures and their cults in various locations—ultimately, this is the book's greatest value to scholars.