It is unclear whether there is anything of historical usefulness that can be gleaned from the details of the depictions of figures such as John the Baptist, Miriai, and Jesus in the Mandaean Book of John. This does not mean, however, that the text cannot provide useful information about the history of the Mandaeans, and of their interactions with other religious communities. By analyzing the evidence for redaction in certain key sections, and by distinguishing between core elements and peripheral additions to the stories recorded in it, it is possible to draw conclusions about the tradition history of the material, which provides evidence of a chronological development in the focuses of its polemic. In so doing, it will be shown that the Mandaean Book of John reflects a tradition which originates within a Jewish context, with either a tangential or chronologically later interest in Christianity, and only later still does an interest in interacting with Islam become a focus.