What are the connections between the polity of the church and church unity - or division? Does the polity of churches serve or obstruct the missional nature of the church? These questions were the focus of the Third Conference of the International Protestant Church Polity Study Group (IPCPSG), held in Princeton, New Jersey in April 2016. The authors of the essays in this volume probe these questions from a variety of angles. The conference intended to model close attention to and reflection on the theological import and value of church order and polity. Attendees of the conference came from churches and denominations in the Reformed tradition, gathering from across the United States and around the world. They included scholars of church order and polity, and practitioners with depth of knowledge and experience gained through the exercise of polity in a variety of settings and contexts. Conference papers, discussions, and informal conversations turned from theological reflection to practice and back.