Summary: The book "Atharvan Zarathustra" delves into a comparative study of Hinduism, Zoroastrianism, and Islam, revolutionizing current views on the mutual relationship among these religions. The author, Jatindra Mohan Chatterji, explores the dissension between the Bhrigus and Angirasas, discussing their spread to Greece and Armenia, shedding light on their Indo-Iranian roots. The text highlights the influence of Mazda Yasna on Islam, drawing parallels between core principles, such as monotheism and aniconism. Additionally, it explores the connections between Sufism and Vedanta philosophy, with a focus on the revival of Gathic Cisti in Iran. The narrative intertwines discussions on key figures like Jalal, Kabir, and Ranjit Singh, emphasizing themes of love, worship, and unity among diverse religious traditions. The book advocates for a holistic understanding of these faiths, urging readers towards a harmonious, inclusive worldview.