Hans Boersma holds the J. I. Packer Chair in Theology at Regent College, Canada, and is co-director (with Matthew Levering) of the Center for Catholic-Evangelical Dialogue. As well as this volume and a forthcoming publication on Gregory of Nyssa, he is the author of Heavenly Participation: The Weaving of a Sacramental Tapestry (2011), Nouvelle Theologie and Sacramental Ontology: A Return to Mystery (2009), and Violence, Hospitality, and the Cross: Reappropriating the Atonement Tradition (2004). Prof Boersma is a member of the Langley Immanuel Christian Reformed Church. Matthew Levering is Professor of Theology at the University of Dayton, USA, where he is also director of the Center for Scriptural Exegesis, Philosophy, and Doctrine. Co-editor since 2003 of the theological journal Nova et Vetera, he has also recently joined the editorial team of the International Journal of Systematic Theology. Prof Levering has served as Chair of the Board of the Academy of Catholic Theology since 2007 and co-directs the Center for Catholic-Evangelical dialogue alongside Prof Boersma. His numerous books and publications include most recently The Feminine Genius of Catholic Theology (2012), Jesus and the Demise of Death (2012), and Predestination (2011). Forthcoming publications include volumes on St. Paul and Thomas Aquinas and on the theology of Augustine.