This book investigates the origins and nature of Gnosticism prior to its formalization within Christianity. Edwin Masao Yamauchi, a noted historian of religion, examines the historical and textual evidence to trace the development of Gnostic ideas. The work analyzes primary sources and scholarly interpretations to present a comprehensive overview of pre-Christian Gnostic thought and its influences.

This scholarly work is recognized for its thorough examination of early Gnostic movements. Yamauchi's meticulous research provides a foundational text for understanding the historical context of Gnosticism. The book is valued for its detailed analysis of complex religious and philosophical ideas.