As I understand it the Dharmic religions prevalent in India/South Asia (Hinduism, Janism, Sikhism) are only mostly confined to India excluding the Indian diaspora, old as new. Buddhism is probably the only Dharmic religion which spread outside of its original homeland (Northern South Asia) to influence the "Chinese Sphere of influence" (East Asia basically).
On the other hand the Abrahamic/Semitic religions can be found in every single country on the planet (in by far most of the world's 200 or so countries they form the vast majority) and on all continents.
True, and it would probably not be wrong to conjecture that there would a near similar spread of Dharmics around the world. Hindu, Buddhist and the smaller other Dharmic faiths which together total around 21% (1.5 billion) of the world population .
Of the 1.6 billion Muslims in the world (23% of the world population), close to 0.6 billion are in the subcontinent alone. Ex-dharmics all.
Of the remaining 1 billion world Muslims, most would be found in the Middle East, and SE Asia (Indonesia).
So regardless of military conquest beyond the borders of the parent faith, the spread of Dharmic and Muslim people around the world, as indeed the numbers in total, would be very close.
I suppose that you are one of the 40.000 or so Zoroastrians in India, am I right? In your case, from what I have heard, conversion of non-natives is not allowed hence you have a different outlook. But like any religion before Zoroastrianism must have spread way outside of the town, city, village, province or land it originated from initially thus also converting "outsiders".
Some of my earlier posts on this forum on Zoroastrianism and Conversion, both with respect to Persia and India.
Conversion to Zoroastrianism
Indias vanishing Parsis | Page 14
Iran - Reversion to Zoroastrianism
Indias vanishing Parsis | Page 14
My belief is that the human race is made up of different people. Different bloodlines and civilizations. Some which grew and continue to this day. Some which died and disappeared.
I believe that part of the process of evolution and the growth curve of every civilization is the genesis and evolution of its theology and faith among its people.
Yes, a faith can be, has been, and probably will continue to be spread by military conquest of different peoples. But in the end a new faith will only take seed in the absence or void of a dominant one. And otherwise revert over time.
Both Hinduism and Zoroastrianism are examples of ancient faiths which spread beyond their borders by conquest and colonization. But eventually the faith came back to its original adherents, replaced elsewhere by other newer and dominant faiths (Buddhism, Islam in SE Asia).
Such I believe will be the cycle for Zoroastrianism and Persia as well. And eventually as well, Hinduism and India.
Christianity being older than Islam is already ahead in the same cycle.Consolidating mainly on lands where the parent civilizational culture is dead (or killed off) or never existed in the first place.
Islam is relatively still a very new faith. The youngest of the major faiths. And it was born in its own place and grew from there. Its conflict of spread with established older faiths for the most part, as by then most of the rest of the civilized world was covered by the great faiths.
This cycle of birth, spread, and reaffirmation and consolidation within the original bloodlines, is one that every faith has and will go through. Which is why I am cognizant and ultimately supportive of the preeminent position of the Arab people within Islam.
In any case although you can say that there is some kind of seniority in Judaism, Islam and Christianity based on who became the first adherents and where it happened it's only bound in historical facts at most as all adherents of those 3 religions regardless of origin are treated equally in the scriptures hence the global emphasis. To guide ALL of humanity and not only a specific people or region.
Like you, I am not overly religious, but I do read a bit, and history and civilizations and conflicts interest me, and from what I've read, it seems that there has been a significant impact of Zoroastrianism on all three Abrahamic faiths. The continuum of Judaism, Christianity, and finally Islam.
A continuum if you will of Middle Eastern monotheistic theology across the ages, with different epochs birthing different Prophets amongst different peoples, from those peoples, of those peoples, for those peoples (from Aryan to the Semitic - which is also why I believe in the blood and soil paradigm of faith so strongly).
To a large extent, Shia Islam is Zoroastrianized Islam. And Bahaiism an even more Zoroastrianized version of the same continuum.
A more culture and race congruent version colored by the parent faith and adopted eventually wholesale by the Persians, who by that time had almost completely become Muslim.
As I understand, Persia immediately after the Arab conquests was largely Sunni first, and became Shia almost wholly some time later. Even though historically Shiism probably originated in what is today Iraq, in the early 1100s and 1200s, it would still very much have been a part of the Persian sphere of influence.
Do excuse the slightly long-winded post, but its a pleasure speaking to an educated and articulate Arab with an open mind on religion.
Cheers, Doc