Summary: In the book "Atharvan Zarathustra -The Foremost Prophet", the author conducts a comparative study of Hinduism, Zoroastrianism, and Islam, exploring the mutual relationship among these religions. The author reflects on the historical connections between these faiths and highlights the role of Zarathustra as a prophet. Drawing parallels between the scriptures of these religions, such as the Gatha and the Vedas, the author traces the influence and interplay of theological concepts. Emphasizing the importance of the Gatha as a foundational scripture, the author asserts the significance of Zarathustra's teachings in shaping religious ideologies. The text also discusses the impact of Sufism as a revival of Gathic Chisti philosophy within the Islamic tradition, advocating for the acceptance of diverse religious perspectives and the unity of all prophets towards a common goal of spiritual enlightenment.