For many people religion is a rigid concept, somewhat like a stone that is passed from generation to generation. We don't add to it, change it, or challenge it; we just pass it along. But even the most cursory study of the history of religions would undermine such a view. Religious traditions are far more like rivers than stones. Like the Ganges or the Gallatin, they are flowing or changing. Sometimes they dry up in arid land; sometimes they radically change course and move out to water new territory. All of us contribute to the river of our traditions. We do not know how we will change the river or be changed as we experience its currents.