This book is a study of the Gnostic religion versus the Roman Catholic Church and other orthodox Christian sects. It looks into the differences in their beliefs in the writings of The New Testament.
The book also explains what Gnosis is. Merriam-Webster Dictionary defines it as "esoteric knowledge of spiritual truth held by the ancient Gnostics to be essential to salvation." In other words, it is what the ancient Gnostics believed to be the truth of spirituality, which was necessary for them to be saved. The book raises questions like whether God is male or female, and whether there is more than one God proven in the Bible.
Elaine Pagels also discusses how the two Christian churches were formed in the beginning and how and why the present version won out. She explains in her book that the legal authority given by the Roman Emperors to the orthodox church eventually led to the lawful persecution of both the Gnostic sects and the pagan religions. She makes it clear in The Gnostic Gospels that Orthodoxy's legal authority nearly eradicated the various groups along with their beliefs, rituals and ceremonies.
She gives a rational explanation for why the Church deemed the Gnostic gospels to be dangerous and banned them. The coexistence of the Gnostic ideas alongside all the other views of Jesus" divinity was a direct challenge to the power structure of the Church. This power was a consolidating one, to strengthen the Church. The orthodox position that developed was aimed at keeping the early Christian movement together in order that it might survive the state persecution of the Roman Empire.
The Gnostic understanding of Jesus took the Church's existence to be unnecessary. It said that one did not have to go through Jesus and the Church, but could approach God on one's own. In later eras, the popes adopted the belief that there is no salvation outside the Church.
I find this to be a fascinating conflict.