Sarah's research examines early modern Christianity from a variety of perspectives: literary, social, spiritual, and intellectual. Other research interests include: Religion and feminism and early modern Britain, gender and history, mystical theology and the Enlightenment, The Cambridge Platonists, and the early Quakers. Currently, she is working on a book about ecumenical pietism in seventeenth-century Britain, arguing that mystical theology represented a critical conversation partner in the epistemological debates which shaped the British Enlightenment.
- Hessayon, A. and Apetrei, An Introduction to Jacob Boehme: Four Centuries of Thought and Reception (Routledge, 2014)
- 'Prophecy and Mysticism in Seventeenth-Century England' in Exploring Lost Dimensions in Christian Mysticism, ed. Nelstrop, L. and Podmore, S. (Ashgate, 2013)
- Apetrei, S., ''The Life of Angels': Celibacy and Asceticism in Anglicanism 1660-c.1700' in Reformation and Renaissance Review, 13 (2011), 247-74
- Apetrei, S., Women, Feminism and Religion in Early Enlightenment England (Cambridge UP, 2010)