Gregg Allison (PhD) is Professor of Christian Theology at The Southern Baptist Theological Seminary in Louisville, Kentucky where he teaches systematic theology. Previously he served on Cru staff at the University of Notre Dame and overseas in Italy and the Italian-speaking region of Switzerland. He is a pastor of Sojourn Community Church, and is the theological strategist for Sojourn Network, a church planting network of about thirty churches. He is the author of Historical Theology: An Introduction to Christian Doctrine; Sojourners and Strangers: The Doctrine of the Church; and Roman Catholic Theology and Practice: An Evangelical Assessment. Chris Castaldo (PhD) was raised on Long Island, New York, as a Roman Catholic and worked full-time in the Catholic Church for several years. After eight years as pastor of outreach and church planting at College Church (Wheaton, Ill.), followed by three years as Director of the Ministry of Gospel Renewal at Wheaton College, Chris currently serves as Lead Pastor of New Covenant Church in Naperville, IL. He is the author of Holy Ground: Walking with Jesus as a Former Catholic and Talking with Catholics about the Gospel: A Guide for Evangelicals. Chris blogs at www.chriscastaldo.com