Religion is a complex issue in Plato Succeeds. Officially, Platonism is not a religion but more of an ethical code and government constitution. However like Confucianism it can be considered a religion in its own right. In the Middle East and Western Europe.
Greece and Rome are the main followers of this faith. As it still exists prominently, the widespread use of Greek and Roman mythology as entertainment in the OTL is either non-existent or diluted to avoid offence. This is especially so in Rome, where Hellenics and Christians coexist but violence could erupt easily. However, the traditional Hellenic faith was attacked by Plato, claiming that real gods surely couldn't be as bad as humans, as they are closer to the Form of the Good; yet the gods are still emotional, vengeful warlike and unreasonable. This has not been seen as an issue in the areas where the Hellenic pantheon have many adherents. The Civilian class tend to favour Zeus, Hera, Apollo and Aphrodite, while the Guardians prefer Ares, Artemis, Athene and the Makhai. Mithras was imported from Persia and is highly favoured by the Guardians alongside the Hellenic gods. This faith has the most followers in the Kallipolic Confederation, though Christianity comes a close second
Christianity is more or less the same, though the New Testament is considered more important. Anything unutopian in the Old Testament is dismissed in the "light of new evidence" while the New Testament was carefully chosen. The Gospel of Matthew lacks 5:17-21 as it places emphasis on the Old Testament, while the letters from Paul to Timothy are missing altogether as they are viewed to contain misogyny. As a replacement, the Gospel of Thomas is included instead. Such events occur in all religions.
The bringer of Christianity to Europe was Paul, formerly known as Saul. A Judean with Roman dual citizenship, he spread the religion of Jesus where he could but eventually turned to Rome. Christianity exists in Europe and the Middle East, along with colonies founded by adhering states. Some communities also exist in Russia, while a large minority is based in Germany. These people included Martin Luther, a reformer who's words led to the formation of the Reform Union, the independent British Kallipolis and the independent Scandinavian Kallipolis.
The Mesoamerican faiths were preserved by the Maya independence movement. Human sacrifice was abolished at the start of the liberation movement. The idea that the world would end in 2012 did not exist as the Maya continued their calendar. North America retains its faiths though works alongside outsider religions such as Christianity.
Eurasian and African
This refers to any other faith in the 3 main continents. The Norse faith is common in Scandinavia, while Shamanism is common in Siberia and parts of Russia. Tengrism is a faith around East Asdia and the steppes. The Norse faith overseas often coexists alongside the Hellenic pantheon. Some philosophers believe that all polytheistic religions gods are the same ones in various guises. A conflict between the European traditional faiths and Christianity may have been a factor in the formation of the Reform Union. One sect however has not survived: the druids were exterminated by the Romans for being too disgusting to live. Their successors in France and Britain have vigorously enforced this ban.
Zoroastrianism is popular in Persia. Adherents find cooperation with other monotheistic faiths surprisingly easy as they have a lot in common.
Islam is based in Arabia and surrounding areas. In this timeline, Islam is as minor as Judaism and serves mainly to unify the Arab peoples. It does not actively seek converts and encourages "militant pacifism". However, a degree of internal conflict has occurred between those who believe anyone can lead Islam (Sunni Islam) and those who believe only descendants of the Prophet should (Shia Islam). A third group, the Kharijites, are famous for their socialist views and disdain for both the Sunni and Shia branches. Islam can be found in Arabia, the immediate area of Asia near Arabia and parts of north-east Africa, such as Somalia.
Kharijites are not considered welcome in Arabia and so prefer to travel. As they split from the rest of Islam before the Sunni/Shia argument and were responsible for the death of the fourth caliph, they want to keep out of the petty feud and form their own mobile Kallipolis. As warriors, they're known for their unwillingness to retreat and have served with distinction is all wars with non-Platonic states.
Judaism is comparatively minor, restricted mainly to Judea. Adherents are split into various groups. Orthodox Jews believe that the Torah and Tanakh are key and should be strictly obeyed. Reformist are more open to Platonism and are more common.
Hinduism is the main faith of the Indian subcontinent. Some adherents impose a caste system on the local populace. All Guardians are of the Kshatriya varna -there's no way they can't be- but the others are more varied. The Brahmin caste have a monopoly on the office of philarchon and so far no dalit has achieved high office.
Buddhism is a faith of the Indian Subcontinent and also widespread among Platonic Chinese. Several Buddhist nations existed in Central Asia, such as in Afghanistan. Buddhists have often been accused of atheism, but manage to withstand such attacks. Some have even adopted gods to compensate for this.
See China (Plato Succeeds). These faiths became more important after the destruction of Confucianism.
A popular side cult is of the Persian sun god Mithras. As in our universe, it is a male only sect, though this was balanced by the cult of Cybele being revised to become all-female. Some faiths are simply not allowed at all such as the druids.
Atheism is allowed as long as the person remains Platonic. This is progress compared to the original demands that are still followed in some more extreme areas such as Greece and the Middle East, where atheists would be imprisoned first offence then executed the next.
Other superstitions such as magic or beliefs in mythical creatures are widely distributed with varying degrees of belief.
This was a highly prominent faith until 1845. After the conquest of the Chinese Empire in 1842, the Confucian school of philosophy was banned and actively assaulted. As a result Cheondoism is also banned as it's seen as a derivative.
Comparison with OTl
Sikhism is not the same as the Islamic/Hindu fusion was not possible. The Bahá'í faith does exist, but is has a Zoroastrian basis rather than Islamic.