It is obvious that some parts of the narratives in Persian literature have taken their themes from ancient Iran, or their origins can be found in Avesta or Zarathustran middle-era Persian texts. However, these stories, originating from ancient Persian literature, have not been unaffected by the Islamic or Semitic principles. These points are even seen in the Iranians’ national epic, the Shahname, so that the gnostic ideas of the beginning of Christianity are seen in the words, thought, and behavior of the characters likes Iraj and Khosrow. The ideas like taking material and human soul and body as evil seem to have, probably, come to Manichaeism from Christianity and from there have entered the Shahname. Also, some speeches made by Persian characters are, indeed, translations of the holy Koran’s words like the independence of god; ‘god doesn’t need offspring or wife’. And, some hints in the words of ancient Iranians show they believed in the angels like Gabriel or Israfil. For instance, Khosrow Parviz talks about a life-taking angel in death-bed while, in Zarathustra, an evil named Astveehad takes human life. In another part, it talks about the knowing of the water of the eternal life by an Iranian farmer. Nowhere in Persian Myths, a trace of Iranians’ awareness of that water and Khezr is seen. The present research deals with the effects of non-Iranian beliefs on the Shahname.