WI Major World Religion founded after Islam?

Mongols united under nestorianism and spreading it during the conquests?
The Mongols in general had a pretty laissez-faire attitude toward religion... they didn't tend to care what God you worshipped as long as a) you didn't fight back and b) you paid your tribute on time, and lots of it.
Nestorianism would also have an uphill battle, being not only a non-Chalcedonian Church but a non-Ephesian Church as well, thus being heretical to pretty much all of the rest of Christendom...
 
Religions founded after Islam, with approximate number of adherents in 1900.

Baha'i100,000
Mormons285,000
Sikhs3 million
Protestants133 million

So, out of a 1900 AD world population of 1.6 billion, the closest to the mark is Protestant Christianity at 8%, with the next runner-up being the Sikhs at 0.2%.

Edit: removed religions founded after 1900.
If we look at the list, the easiest way would be to make Protestants seen as none Christians-which is highly unlikely/borderline ASB-or make Sikhs more prevalent (although the Indian subcontinent already has at least three other major religions- or, um, some big Mormon-wank. Baha'i would be difficult to wank because essentially they believe everyone-is-right. This makes it difficult, because why convert away from your native religion when this new faith tells you your right? You could do it no matter what after Islam was founded, but in a recognizable world it is very hard to do.
 
Well, the Punjab, Sindh, Baluchistan, maybe even Afghanistan and basically asserting a stronger role into East Africa, maybe from Somalia down across and maybe spreading into the mainland? That's not an insigificant growth though.

Like the idea of ATL Sikhism making gains in Sindh, Baluchistan (possibly including Iranian Baluchistan if we are referring to the region in general as opposed to Afghan and Pakistani parts of Baluchistan?) and Afghanistan as well as possible gains in parts of East Africa (and less likely Southeast Asia), just that have seen previous threads dismiss the idea of a wanked Sikhism taking hold beyond the Punjab region and possibly parts of Sindh.
 
Like the idea of ATL Sikhism making gains in Sindh, Baluchistan (possibly including Iranian Baluchistan if we are referring to the region in general as opposed to Afghan and Pakistani parts of Baluchistan?) and Afghanistan as well as possible gains in parts of East Africa (and less likely Southeast Asia), just that have seen previous threads dismiss the idea of a wanked Sikhism taking hold beyond the Punjab region and possibly parts of Sindh.
It’s unlikely, but people would convert over time for a variety of reasons and would grow from there
 
Mongols united under nestorianism and spreading it during the conquests?
Maybe a Native American/ South American organized religion taking elements from Christianity and traditional belief systems.

Or an Pan African faith popular enough to stop Abrahamic religions to spread.
 
Maybe a Native American/ South American organized religion taking elements from Christianity and traditional belief systems.

Or an Pan African faith popular enough to stop Abrahamic religions to spread.
There are a lot of native american and afro-american beliefs in South and Central America that took elements from christianity. In Brazil you have Umbanda as an example.
these types of religion never were too popular because Spain and Portugal always strengthened catholicism in their colonies.
 
This is probably gonna be very unlikely, but the Baha'i could grow to a decent hold in Iran and spread from there.
 
If Musaylimah the liar or any one of the other false "prophets" can defeat the Rashidun forces and win the Ridda Wars, then there might be a possibilty for another religion to arise from there.
 
A successful Taiping Rebellion would lead to something becoming a major world religion.
Not sure about that... Taiping was so idiosyncratic and so personality-cult driven (yeah, I know, like that makes it exceptional as far as religions go :p) that it's hard to imagine it surviving for long after the Little Brother of Christ had passed on... it would be like Jim Jones's People's Temple surviving, just on a much larger scale...
 
If you consider catharism and the assorted Christian Gnostic groups ie the Paulicians/Bogomils to be a seperate religion, then that could be counted
This reminds me of a conversation from a thread a few years back (iirc).

The basic premise was that the Nag Hamaddi Library gets discovered way earlier than OTL, leading to a Gnostic revival. By choosing select doctrines, anti-semites have what they always wanted in a non-jewish Christianity to the point of “Gnozis” forming.
At the risk of going a bit off-topic and post-1900 - well, you'd think that about India, but here's a rather new one (or a new take on a very old one at least) that looks pretty promising:

Tbh, I don’t see that getting much traction. Whilst there has always been a lot of debate over what Siddartha taught, Navayana isn’t really that close to any seriously considered scholarship on the subject.
I think Sikhism or Mormonism would have the best chance of becoming big by the 21st century. The problem is both faced a lot of persecution in their early years, which probably hampered their growth.
Mormonism is super limited in it’s potential to spread tbh. Between genetics, Archaeology and the whole Book of Abraham debacle (which debunks the entire faith on its own without considering the former two), the Mormon faith really benefits from being obscure.
 
Seems like the more likely option other than Sikhism would be a more radical/different Protestant reformation. Though what about a Reformed Islam? Maybe a Mutazilla-derivate becomes super popular at some point.
 
It’s unlikely, but people would convert over time for a variety of reasons and would grow from there

Understand, all the better if it manages to become a majority in most of Punjab, Sindh, Baluchistan and other parts of Afghanistan.

Seems like the more likely option other than Sikhism would be a more radical/different Protestant reformation. Though what about a Reformed Islam? Maybe a Mutazilla-derivate becomes super popular at some point.

A wanked Mutazilite derivative could work.

Also like the notion of one or a few Post-Islam sects becoming popular, basically think something like early Baha'i (or an Islamic analogue of Mandaeism / Manicheanism) with a Sikh / Gurkha like warrior culture, Omani/Sikh-like Empire and possibly even a Mongol-like fearsome reputation.
 
Understand, all the better if it manages to become a majority in most of Punjab, Sindh, Baluchistan and other parts of Afghanistan.

It would become the majority in the Punjab while it will take a while longer in other places though the various zeitgeists would make it likely to change, especially with the decline of Muslim nations and the past grievances perhaps convincing newer generations to embrace Sikhism over time.

And for the Africa thing, it'd be done faster given how it would be seen as a liberating force against slavery and probably flexible enough to incorporate the local culture into it without too much trouble or worry on it. It would probably spread into further the center of Africa albeit with even more syncretism. I don't see it doing more elsewhere unless this Sikh Empire somehow gets more offshore presence. Maybe they beat the Dutch to claiming Papua New Guinea, but that's just an odd longshot (still possible) and that could lead it to spreading across Nusantara.

Beyond that, it's more difficult to say unless the Sikh Empire expands northward to Central Asia (unlikely though the influence could still be there, especially if the Khanates or former Emirates come to rely on them)
 
This might be a stretch but what about something like Mormonism becoming so popular that it becomes the United States' official and majority religion?
 
10 to 20 percent is a big ask. But still, like all "world religion" questions, this hinges fundamentally on the definition of "religion". Is Ahmadiyya, for example, a distinct "religion" from Islam? In that case, you could have an analogous Mahdi claimant relatively early on just sweep half of Islam off its feet and then wank that sect to the stars. Are the various Hindu sects distinct "religions"? In that case, a relatively small change in Indian history around the time of the Mughals / early colonisation could bring about a novel Hindu sect that manages to gather a majority of Hindus as adherents. Could a semi-egalitarian, stripped-down, proselytising variety of Zoroastrianism have picked up in a post-Sassanid, non-Muslim Persia, and converted the Turkic peoples who were to define so much of medieval Middle Eastern and South Asian history? Sure, but you might as well just call that "Zoroastrianism", right?

If you go by the most stringent definition (a religion as wholly distinct from its influences as Islam), honestly, I think 10-20% is a bit too tall of an order. Islam filled in a very wide gap: a unifying set of uncompromising principles and a community among the Arab people, whose population and social inequality had gradually grown to an unsustainable point. After Islam's rise, there really wasn't a place on Earth where the conditions that give rise to a viable proselytising religion would exist up all the way until industrialisation, IMO. The Subcontinent is a possible exception, but it seems to have given rise to sects like Sikhism and Lingayatism that take off on a flying start and then peter out within a particular region. And East Asia, to be honest, is just right out. The Confucian state did not tolerate challenges to its self-preservation as such, so while a bunch of sects more or less distinct from Buddhism and unorganised local tradition have arisen there, none have gathered the momentum to approach state-level power, let alone a significant percentage of the world's population.
Maybe have a big polythesing faith appearing in Africa. Something akin to the Serer religion in West Africa (actually a ethnic relogion) or another one. African regions had a rich history of their own complex faiths and cosmology.
Or have a religion early on spread in South and Middle America combining Catholic elements and aboriginal beliefs into a new religions with a widespread followership.
 
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