The chapters that give the book its name tell John's story as the Mandaeans hold it. His birth is heralded by a star over Jerusalem and by portents that alarm the priests; the child is protected, raised in purity, and grows into Iahia Iuhana the baptiser, who takes his stand at the Jordan and administers the baptism of living water that is the Mandaeans' own central rite. The discourses put long first-person proclamations in his mouth: the fisher of souls who casts his net for the children of light, the good shepherd, the physician whose medicine is the word, images that echo and invert the language familiar from the Christian gospels, for the book's relation to Christianity is openly polemical.
In its most discussed scene, Jesus comes to John asking for baptism, and John at first refuses him; the baptism proceeds only on instruction from the world of light, and the tradition marks Jesus as one who altered and betrayed the baptiser's religion. Scholarship reads these narratives not as independent history of the first century but as the self-definition of a baptising community distinguishing itself from an ascendant Christianity, exalting John as the true prophet against the rival's founder. Around the John material stand discourses of other figures, Anush Uthra the heavenly envoy among them, and sustained moral preaching on the soul trapped in the body, warned, admonished and called upward.