The influence of Zoroastrianism on Vedic thought can be seen through shared roots and ideas between the two ancient religions. The Vedic texts, composed between 1500 BCE and 500 BCE, show evidence of borrowing from Zoroastrianism, which emerged in Persia around the same time.

One of the most significant shared roots between Zoroastrianism and Vedic thought is the concept of a supreme deity. In Zoroastrianism, this deity is known as Ahura Mazda, while in Vedic texts, it is referred to as Brahman. Both religions believe in a single, all-powerful creator who is responsible for the creation of the universe. This shared belief suggests a common origin or influence between the two religions.

Another aspect of Zoroastrian influence in Vedic thought is the concept of duality. Zoroastrianism teaches the existence of two opposing forces, good and evil, represented by Ahura Mazda and Angra Mainyu, respectively. Similarly, the Vedic texts mention the concepts of devas (gods) and asuras (demons), representing the forces of good and evil. This parallel suggests that the Vedic authors may have been influenced by Zoroastrian ideas of duality.

The Vedic texts also show evidence of borrowing from Zoroastrianism in their beliefs about the afterlife. In Zoroastrianism, the soul is judged after death and sent to either heaven or hell based on one's actions in life. Similarly, the Vedic texts mention the concept of karma, where one's actions in this life determine their fate in the afterlife. This similarity suggests that the Vedic authors may have been influenced by Zoroastrian ideas of judgment and punishment in the afterlife.

Furthermore, both Zoroastrianism and Vedic thought emphasize the importance of ritual and sacrifice. Zoroastrianism has a complex system of rituals and prayers, while the Vedic texts mention various sacrifices and rituals to please the gods and ensure prosperity. This shared emphasis on ritual suggests that the Vedic authors may have been influenced by Zoroastrian practices.

In conclusion, there is strong evidence of Zoroastrian influence in Vedic thought through shared roots and ideas. The concept of a supreme deity, duality, beliefs about the afterlife, and emphasis on ritual and sacrifice all suggest a borrowing or exchange of ideas between the two ancient religions. This influence highlights the interconnectedness of ancient civilizations and the impact they had on each other's beliefs and practices.