Zoroastrianism is one of the world's oldest monotheistic religions, founded by the Iranian prophet Zoroaster. It believes in a supreme creator god Ahura Mazda who is all good and the source of all goodness and happiness. Zoroastrianism also believes in an ongoing cosmic dualism between good and evil, with Ahura Mazda battling the destructive spirit Angra Mainyu. Followers have free will to choose the path of righteousness or deceit. After life, the soul is reunited with its guardian spirit. Dead bodies are exposed to prevent decay and pollution of the world until the final renovation when good will triumph over evil.