According to anthropologists John Monaghan and Peter Just, "Many of the great world religions appear to have begun as revitalization movements of some sort, as the vision of a charismatic prophet fires the imaginations of people seeking a more comprehensive answer to their problems than they feel is provided by everyday beliefs. Charismatic individuals have emerged at many times and places in the world. It seems that the key to long-term success – and many movements come and go with little long-term effect – has relatively little to do with the prophets, who appear with surprising regularity, but more to do with the development of a group of supporters who are able to institutionalize the movement." 
Hick argues for what he calls the “pluralistic hypothesis”: that Ultimate Reality is ineffable and beyond our understanding but that its presence can be experienced through various spiritual practices and linguistic systems offered within the religions. The great world religions, then, constitute very different but equally valid ways of conceiving, experiencing, and responding to Ultimate Reality. He uses different analogies to describe his hypothesis, including an ambiguous picture of a duck-rabbit. A culture that has ducks but no familiarity with rabbits would see the ambiguous diagram as a duck. People in this culture would not even be aware of the ambiguity. So too with the culture that has rabbits but no familiarity with ducks. People in this culture would see the diagram as a rabbit. Hick’s point is that the ineffable is experienced in the different traditions as Vishnu, or as Allah, or as Yahweh, or as the Tao, and so on, depending on one’s individual and cultural concepts.