Ted Peters is professor of systematic theology at Pacific Lutheran Theological Seminary and the Graduate Theological Union, Berkeley, California. Michael Welker is senior professor at the University of Heidelberg, Germany, and executive director of the Research Center for International and Interdisciplinary Theology. He is the author or editor of dozens of books, including God the Spirit, The Work of the Spirit, God the Revealed, Creation and Reality, What Happens in Holy Communion?, and The Depth of the Human Person.

