The Secret Book of John (Apocryphon of John) is a 2nd-century AD Sethian Gnostic Christian text of secret teachings. Since it was known to the church father Irenaeus, it must have been written before around AD 180. It describes Jesus Christ appearing and giving secret knowledge (gnosis) to the apostle John. The author describes this having occurred after Jesus "has gone back to the place from which he came". This book is reputed to bear this revelation.
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