Zoroaster Moses, Jesus and Muhammad had all brought them, so why did you not believe in any of these prophets, having believed in Zoroaster, through the tales that came to you about him, informing that he brought forth what others did not?” Ahmadi Muslims view Zoroaster as a Prophet of God and describe the expressions of Ahura Mazda, the god of goodness, and Ahraman, the god of evil, as merely referring to the coexistence of forces of good and evil enabling humans to exercise free will. Mirza Tahir Ahmad, the fourth Caliph of the Ahmadiyya Muslim Community, in his book "Revelation,
Medes of the Indo-Iranian word "arta-" (lit. "truth") which is familiar from both Avestan and Old Persian and also examples of theophoric names containing "Maždakku" and also the name "Ahura Mazdā". Scholars disagree whether these are indications of Zoroastrian religion amongst the Medes. Diakonoff believes that "Astyages and perhaps even Cyaxares had already embraced a religion derived from the teachings of Zoroaster" which was not identical with doctrine of Zarathustra and Mary Boyce believes that "the existence of the Magi in Media with their own traditions and forms of worship was an obstacle to Zoroastrian proselytizing there". Boyce wrote that the