The essays in this volume, in different ways, invite the reader to consider Catholic identity not only in terms of who we are but what are we for? To be sure, identity and mission are deeply interconnected but offer different starting points for reflection on formation. The authors of this volume, working in Catholic higher education, elementary and secondary education, Catholic social services and pastoral ministries-articulate a number of challenges when it comes to formation around Catholic identity. How does the Catholic identity of a college or university enter into the curriculum and institutional practices of a community? How does Catholic identity contribute to the training and self-understanding of educators in elementary and secondary schools? How does an organization inspire and empower the laity into leadership? At the heart of these questions is the challenge of building the common good within the Church and for the world.