Ahura Mazda is the God of the Zoroastrians. In their scriptures (I believe it's called the Zend Avista) it states that only Ahura Mazda is God and all other gods (I assume that includes Yahweh) are idols. Their scriptures also have prophecies (lots of holy books do) that have been fulfilled. To top that off it also contains eyewitess accounts of miracles performed by their God. Ahura promises eternal life if we serve him. Jesus claimed to bring eteral life to those who believed in him. Both are allegedly sinless and people have claimed to have seen and spoken to Ahura Mazda as well with Jesus. Both lack historical proof. How would anyone know which one to have faith in if they both make the same promises without evidence? Excuse the typos, I'm on my cell phone doing this.