 Despite a belief in reincarnation , the Lingbao School maintained the traditional Daoist idea that certain techniques could allow an adherent to achieve immortality . One technique was to ingest the essence of the sun and the moon . Practitioners would expose themselves to the celestial bodies at certain times of the month . Closing their eyes , they would visualize that the essences would solidify and enter their bodies . Once in the body , the sun 's essence was matched to the heart and visualized as red , while the moon 's was matched with the kidneys and seen as black . Besides interior meditation practices , immortality could be achieved through the ingestion of potions or talismans . 
