Professor McGrath's research interests include early modern literature and, in particular, the influence of the Reformation on devotional poetry and prose. His first book, Early Modern Asceticism: Literature, Religion, and Austerity in the English Renaissance (University of Toronto, 2019), recovers a cultural and literary history of asceticism after the English Reformation and the institutional moorings of the ascetic life (e.g., monasteries, clerical celibacy) had been dislodged. It argues that ascetic debates about the relationship between the body and the soul had a major impact on conceptions of sexuality, subjectivity, and embodiment in the early modern period. With Regina Schwartz, he edited Toward a Sacramental Poetics (Notre Dame University Press, 2021). The book features a collection of essays by theologians, philosophers, literary scholars, and artists on the enduring presence of sacramentality in early modern and modern culture. His second monograph, Unyielding Hearts: Sexual Indifference in Shakespeare, Milton, and Marvell, examines idealizations of escaping sexual desire in the literature and religion of the early modern period. He has published articles in The Review of English Studies, Studies in Philology, Religion & Literature, Milton Quarterly, and Prose Studies among other venues.