We've been over this many times in the past.
Simply put, the Persians as a race were far ahead of their times.
God sent them His message through Zarathustra first.
The Arabs, long subjugated, and pagan tribalists for the most part of that history, finally received the message through Muhammad last.
That you (Muslims) would like to believe that it was the final message, the truest message, the most refined modern relevant for the times message, the most universal message, is your belief.
And you are welcome to it.
Scholars who study these things find undeniable borrowing of major concepts and belief plinths of the Semitic Abrahamic faiths, all three of them, from Aryan Zoroastrianism that came much earlier, and impacted all three faiths, their people, and their region and politics, for thousands of years.
If the message remains the same, if God is one, and He sends his Prophets from time to time to people, WHEN they are ready, WHEN their need is most dire, and birn from WITHIN them, then whether you call the man-organized religion by a different name, or call God Himself by a different name, and have the message in different texts, written and read in the language of THOSE who it was MEANT for, then it's pretty clear that once you sift the core concepts from the rest of the so called "differences", you are left with what are essentially people-soecific rule books.
Relevant to the time, place and persons.
Not universal. Unless of course enforced by sword and doctrine.
Mass brainwashing. Followed by the inevitable revisionism and theological muddle.
And then, conflict. Which is only too evident among both Christianity and Islam.
That's what happens when a faith is spread by man to people God did not intend it for.
And the results we see everyday. Across the Christian and Muslim worlds.
I am short on time, so for the time being I will be posting a brief short reply
You are mixing man made politics, rituals, practices and are labeling them borrowed ideologies from Zoroastrianism and now are under the banners of Christianity and Islam ......... I requested you to please read Quran and then tell us how is it similar to Zoroastrianism? I am not an Arab ....... why am I convinced by Quran's message? Or forget me, do you think Maurice Bucaille was an Arab too? Do you know how many white people in today's world have converted to Islam? Do you think all of them are made Muslims by brainwashing or swords?
There must be something unique to the message Doc that appeals these educated people to accept it.
Arabs took control of Persia ...... people converted in masses ....... and still today they celebrate Noroz, we see those idols and statues .... if Muslims of that time had acted like the victors did in those times (which you think they did all barbarian and looters) .... then how do you deny all these facts and same old rituals?