"Hultgren and Haggmark have brought together in one volume all of the major orthodox references to persons and theological movements of the first two Christian centuries that were subsequently branded as ’heretical.’ In so doing, the editors have done a great service for instructors in early Christian history.... The volume’s brief introduction not only helps contextualize the heterodox thinkers or movements in their time but also helps relate the concerns that they addressed in the first and second centuries to those of the late twentieth century.... For those readers as well as for scholars who would like to have a ready reference, this is a useful volume."
-- Church History
"The Earliest Christian Heretics is a ’user-friendly’ anthology that will be a great help to both the beginning student and specialized scholar and teacher of early Christianity. Whereas once the researcher had to rifle through the cumbersome volumes of the Ante-Nicene Fathers series, now she can reach for this handy compendium to find all major heresiological entries for the first two centuries presented in a simple, clear format."
-- Journal of Early Christian Studies
"A highly useful compendium of well chosen early Christian writings (in English) directed against a wide variety of heretics, especially Gnostics."
-- Robert M. Grant, University of Chicago
"This book fills a surprising gap. It is highly recommended as a classroom resource for college and seminary, a study guide for the interested nonexpert, and even a handy tool for the graduate student of scholar for quick reference to sources otherwise scattered."
-- Carolyn Osiek, Catholic Theological Union