Hmmm. "Communion" is closely based on the "Last Supper" of Jesus---- the Passover Seder that took place the evening before the Romans soldiers crowned him with thorns, mocked and whipped him then nailed him to the execution stake. And Passover is no way based on Zoroastrianism.
"Baptism:" This is based on the Jewish ritual mikveh bath that represents cleansing or repentance. Next time you go to Jerusalem, check out the ruins of these baths just outside the current south wall of the city, between the "Dung" Gate and "Zion" Gate.
I don't believe the Zoroastrians practiced the salvation story of Passover, or an immersion of repentance. Please point me to where I can be disabused of this belief.