This is a wonderful reference library to give the reader a taste of the different Gnostic literatures existing in the Christian world. I especially liked how the compilers delineated the different gnostic groups and then gave a sampling of that particular group's literatures, from the Sethians to the Valentinians, to the Cathars and the Mandaeans.
I found their section on Manichaeism and Mandaeism particularly interesting, being that Manichaeism was one of the competing religions of the day, relative to how Appolonius was a contending contemporary of Jesus. Mandaeism is just exciting in itself, called the "Christianity of John the Baptizer" where Jesus Christ is seen as a false messiah to John the Baptizer.
I highly recommend this to Christians votaries of all walks of life, whether it be of the laity or of the clergy. It definitely breaks with the modern, Trinitarian Christian organisation and gives ponderance upon an alternative Christianity that was once, and still is, considered blasphemous.