A Popular Guide to the Mass is a theological and pastoral guidebook or explanation of the Catholic Mass liturgy, intended for lay readers. The book's general themes include: Exploring the deeper theological meaning behind the elements of the Mass, such as the Eucharist (Holy Communion), the priesthood, and the presence of Christ. In short, the book aims to help readers understand why we do what we do at Mass and to enrich their spiritual experience during the liturgy.