Francis Crawford Burkitt (1864–1935) was a prominent theologian and biblical scholar. Originally published in 1932, this book contains the substance of five lectures delivered by Burkitt during October 1931 at Union Theological Seminary, New York, as the Morse Lectures for that year. Various aspects of the relationship between Church doctrine and Gnostic thought are discussed, providing a highly informative analysis of a complicated topic. Rigorous and thought-provoking, this text will be of value to anyone with an interest in the early development of Christianity and biblical scholarship in general.