This classic by Harnack was an epoch-making historical work that set the standard for any history of doctrinal development. Harnack locates the origins and traces the development of the authoritative Christian doctrinal system from its beginnings down to the Reformation, with a brief survey of later developments through 1870.

This brief but thorough treatment of the history of the doctrines of Christianity starts out by showing what the structure of belief was that started with Jesus teachings and how that affected the teachings and spread of the Gospel from Jesus through the Apostles to the early catholic church. The next topic dealt with is the rise of one of the greatest heresies in the church, Gnosticism. Harnack is able to observe and lay out how the spread of the doctrines of the early church were able to create a breeding ground for the gnostic heresies and goes over the details of some of those heresies. This treatment of the early church is a valuable tool to any true scholar!