About five centuries ago, the modern world started. This was the first successful challenge to the power of the Hapsburgs, in religious issues.
After the success of the Crusades, the power of the Pope was so unilateral and unchallenged that they did things I think that they would later regret. The period of reform goes back to the time of at least Saint Francis of Assisi. Most of the reforms the Roman Catholic Church tried to wipe out, by killing everyone, as they saw it as a revolt and heretical.
By the time of the Protestant Reformation, the Hapsburgs were the big world power everyone else wanted to defeat. They included the entire empires of both Spain and Portugal, which included most of the tropics around the entire world, as well as big parts of modern Belgium, Germany, Southeastern Europe, and Italy, at one time.
This was around the time, when the armies of central and eastern Christian Europe combined and finally found some success against the most powerful Islamic Empire of the time, called the Ottoman Empire. This empire covered most of what we now think of as the Arab world. They actually did not become mostly Arab and Muslim, until the early 20th century though.
The real instability occurred, when France decided they did not want to be part of the Habsburg Empire. To achieve this, they decided to ally themselves with the Ottoman Empire. France decided to fund the new Protestant movement, in what is now called Germany. At the same time, the French persecuted their own people, who converted to Protestantism.
After fighting a number of wars, some world wide, the French finally agreed to stop interfering in the internal affairs of the Holy Roman Empire, in what is now Germany. The other end of the deal was that the Hapsburgs were to let those in this Pre-German area choose to be a variant of Protestantism. This was only on the condition that local rulers had previously converted first. This is the very first treaty of what later became the legal basis of modern international law. This was the start of what we call things like human rights.
The theological explanations are all over the map and the exact issues are not interesting, to most people today. Suffice it to say, they are essential irresolvable issues. One of the major issues is the interpretation of Scripture. Many people, on both sides, felt very strongly about this. They decided to confess their beliefs in public, knowing full well that they would be executed the next day for it.
The Churches basically were at each others throats, until the time of Napoleon. Napoleon was a dictator who ruled France, because after the French Revolution was finished killing their king and queen, they could not agree on anything.
Napoleon hated the Catholic Church. He looted it to fund his war campaigns. He also set the course for the founding of modern Germany and modern Italy. Additionally, he finished off the Spanish and Portuguese empires, that were already weak by then, both directly and indirectly.
After he was defeated, the eastern half of the Hapsburgs empire ended up being weak. They were in this position, because they lost the other half of their Empire, about a hundred years earlier. They decided to stop marrying outside the family, so they didn’t have to give up power to foreign rulers. They ended up losing the Spanish Empire part to France basically.
So the big powers still left in Europe, with substantial armies, were the British and what was left of the Habsburg Empire. So the Hapsburgs strategy was to shift alliances and make peace with former enemies. This decision allowed them to avoid having to fight more than one country at a time.
So they made this peace treaty with the British, that all of Europe honored, until World War I. This was the height of the British, French, German, and Italian empires. These countries basically took over the areas of the Arab and Muslim world and their areas of influence from Africa to Southeast Asia, because those empires became weak. This all happened in a very short amount of time.
Around this time, there were about 5 major revolutions including the French, American, Enlightenment, scientific, and romantic. This all lead to nationalism and World War II, where Europe finished destroying what was left after World War I and they lost their empires. History textbooks of most countries divide themselves into 3 sections. Before the 19th century, the period up to 1945, and after 1945. These correspond to the major technology revolutions.
This history goes back to Christianity getting involved in politics, which I think is a mistake. At the onset of the Middle Ages, Western Europe ended up joining together Church and state, to solve a very obvious problem then. The churches in the east ended up being terribly persecuted. The common factors are that they both got involved in politics. They were then manipulated to give one group in power justification for their policies.
So the problem is that the Church wants to have unity, while maintaining a certain set of doctrines. One of the big challenges, that may just not be possible, unless we radically change how we look at Scripture, is that you cannot have unity and consistent doctrines over time. This goes back to how the Bible is written more in a literary style than a legal document.
Part of the problem is that we look at it in a culture that is anti-intellectual, anti-supernatural, and very political. What did God intend though?
I personally think that God wanted to force us to decide to fully embrace His ideas or entirely reject them. I think we are going through an existential crisis as a Church, a world culture, and in the minds of every person on the planet. I think God is a romantic at heart.
I do not believe God will come back in my lifetime, though. I think that God uses forces that do not correspond, to political parties. He uses weather, economics, and technology, to drive change in cultures and in individual people’s lives.
Many people, in a small part of the world, believe God is irrelevant to them, but most of the world today and almost all of the world throughout history strongly disagree.
I believe that religion is already becoming more influential in America today, in the mainstreaming of feminism and science fiction. I do not believe it follows party lines though. The most popular idea in politics today is to not vote.