Description
Another product of daydreaming in Japanese history class: one where the Shimabara Rebellion succeeds. In this timeline, rather than helping crush the Shimabara Rebellion, the Dutch help the rebels. This is due to the rebels having a much more successful early stage, which led to the Dutch refusing aid to the Tokugawa, which led to the Tokugawa threatening the Dutch, which led to them assisting the rebels in a bid to create a more foreigner-friendly Japan[1]. This succeeded, but only partially: the Dutch-backed Amakusa Shogunate was created, and it helped bolster Dutch power in the Pacific and throughout the world.
This had some knock-on effects around the world. The Chinese expelled Christian missionaries from their country, as Christianity was seen as a subversive force. This led to a souring of relations between China and the West, eventually culminating in a series of "humiliation wars" that led to much of southern China under colonial European domination. The union between Spain and Portugal survived, the relationship between the two gradually growing closer to the point that everyone thinks of Iberia as one political entity. The Dutch and the Iberians dominate the waves up until the modern day, although they've had hiccups particularly with the rise of the British as a dominant naval power and the loss of much of the New World to independence movements.
The world remains divided broadly between the Catholic and Protestant worlds, particularly after the 18th century Habsburg Wars led to the creation of a unified, Habsburg-led, German-speaking Holy Roman Empire that became the dominant continental European power. A few Protestant German states remain independent, and extremely anti-German. The old Dutch and Iberian colonies have become entangled in alliances with their mother countries. Christianity is more fractured and dogmatic than OTL; there is no one "Christian" identity, but Protestantism has fallen under one umbrella to oppose Catholicism. Both sides are far more socially conservative, although with some slight differences (Protestants are more friendly to controversial ideas like evolution, while the Catholics have said that contraceptives are okay). Christian fundamentalist terrorism is common, targeting the opposing sect. Ironically, non-Christian religions aren't seen as a threat, mostly because they are in "other parts of the world." Immigration policy is very strict, with explicit religious and cultural tests, throughout most of the world, and even then only the most skilled workers are admitted. Exceptions exist in the settler colonies of the New World, who allow for mass immigration, but even they only take in co-religionists. The idea of multiculturalism would be laughed at. Racial discrimination isn't as vilified as OTL, but "civilize and convert" is the general attitude.
Politically, monarchs remain powerful, although the Protestant ones do have to content with democratically-elected legislatures, who have the exclusive power of the purse. The British, Dutch and their former colonies have written constitutions outlining the rights of the citizen[2], nobody else does. Public worship is only legal for recognized faiths, although "heretics" who worship in private are ignored unless they are threats to the state. In the New World, states tend to be more religiously dogmatic; while burning at the stake is too 15th century, heretics are often arrested for "disturbing the peace" and kept in labor camps. Virginia in particular still enforces laws against witchcraft.
India is fragmented, and more Catholic and Protestant than OTL; the Europeans have been more zealous in their conversion efforts than OTL. This has led to the creation of many new and weird sects, mixing Christianity with Islam, Hinduism, and Buddhism. These radical sects often attack one another openly, despite efforts by the European colonial authorities to clamp down on. China has adopted Western technology, but is staunchly opposed to European cultural influence. China is rapidly industrializing, and the Europeans fear that they might be eclipsed in the future.
The world has never had a conflict on the scale of the Great War, although the Habsburg Wars resemble the Napoleonic Wars in scale. Nuclear weapons have been invented, but have never been used in anger. There has been no arms race at the same scale as OTL, and nuclear weapons are smaller and seen as tactical weapons; no city-busting strategic weapons on the scale of OTL hydrogen bombs exist. Color television is the main means of communication, and most networks are heavily censored or owned by the state. Computer technology is way behind, close to the OTL 1940s, and telecommunication and electrical networks are far more fragmented. Economically, most people are poorer than OTL, and there isn't much of a car culture; most transit is via train, bus, or bike. Roads are much smaller, and there are almost no highways to speak of outside of New Spain. The Catholics are trying to build a continental rail network in Europe, but debates continue on which gauge to use.
[1] Even if they were Catholic.
[2] This includes freedom of worship, except for "threatening religions" such as Catholicism.
EDIT: Added Protestant German states.