The common element in every religion is the promise of an afterlife of some form. There is an assumption that humans have duality - a physical component and a spiritual/soul component. We can define religion then as - A set of beliefs that some form of potential continued existence will occur after physical death. To ensure the promise is fulfilled and/or to determine the quality of the after death experience - requires obedience to a set of rules that describe - lifestyle, morality, and rituals. These details determine how each religion will differ from any other. These include theistic and non-theistic religions. The scope of the details appear to be limited only by human imagination, and in many cases some details will be in direct conflict with other religions. If duality is false then all religion is pure nonsense and has no purpose. If duality is true how could we determine what set of imaginative guidelines might be true, if any? From reincarnation to heaven or hell, etc? Is there any evidence that duality might be true or is even possible?