What Dreams May Come in the book are derived from my wide range of reading." One of Matheson's influences was Harold W. Percival, an adherent of Theosophy, a belief system with a strong Eastern and Hindu influence. The story also shares the same theme of the ancient Greek myth Orpheus and Eurydice, in which the gifted musician makes a challenging journey to Hell to retrieve his wife. One character quotes from the writings of 18th century Christian mystic Emanuel Swedenborg. Matheson bases his descriptions of the death experience itself on studies by Elisabeth Kübler-Ross and Raymond Moody. When reading these accounts, Matheson found that
Orpheus under Medea's guidance, is reflected in the Biblical story of Lot's wife when escaping from Sodom. More directly, the story of Orpheus is similar to the ancient Greek tales of Persephone captured by Hades and similar stories of Adonis captive in the underworld. However, the developed form of the Orpheus myth was entwined with the Orphic mystery cults and, later in Rome, with the development of Mithraism and the cult of Sol Invictus. According to a Late Antique summary of Aeschylus' lost play "Bassarids", Orpheus, towards the end of his life, disdained the worship of all gods except the sun,