I suppose for certain cultures the proof is validated in there beliefs and personal experiences. Tibetan, Buddhist Monks, Indian Swamis have believed and validated there beliefs for thousands of years with personal accounts of AP/OBE. It's not as if we start from scratch. I just seem to know this is real and God is real. If more valid proof is required we could always go to Tibet and meditate 18 hours a day to achieve a higher level of projection or Calcutta to wear a loincloth, get buried in the dirt and fast for 28 days straight.