He is the author of Cultivating Perfection: Mysticism and Self-transformation in Early Quanzhen Daoism (2007), The Way of Complete Perfection: A Quanzhen Daoist Anthology (2013), The Daoist Tradition: An Introduction (2013), and Daoism: A Guide for the Perplexed (2014), and the editor of Contemplative Literature: A Comparative Sourcebook on Meditation and Contemplative Prayer (2015).