Not a true gospel, but a text of the sect of Kindred?

I was particularly disappointed after reading this book.
Of course the authors, repositions the gospel in context, particular stress on checks made regarding the authenticity, not the author, but the manuscript, so the content is foreign to what one can find in the other gospels, apocryphal or canonical.
This text, probably dating from the late second century, has content that the book's authors classify as Gnostic, and about allegedly sent by Christ.
At the end of this book, I'm still not convinced that the statements contained in this text can be attributed to Judas Iscariot. The book remains nevertheless be interesting to those who are interested in the sect of Cainites.