This book is devoted to understanding the confessional foundations of church unity in the earlier theology of Karl Barth. This book follows Barth's academic and ecclesiastical career from the years 1921 to 1938 as he moves from a nonconfessional pastor in Switzerland prior to his first teaching post in Gottingen to articulating, in his first volume of Church Dogmatics, the critical and essential authority of the church's confession in its public witness at the start of his final teaching post in Basel. During these years, each academic placement and public ecclesiastical assignment is crucial for understanding the development of Barth's confessional theology in order to make sense of his mature dogmatic understanding of the authority of the church's confession in CD I/2.