The two things some of us were taught never to discuss in social situations. Reading The Silk Roads, A New History of the World, simply reaffirms why those who wrote the United States Constitution insisted on separating religion and politics. Mixing the two leads to tyranny, war, misunderstanding, and a host of other ills. When did this mixture start? Prehistory or at least the early recorded history.
Constantine, the Roman emperor, converted for political purposes. The Persians tolerated a wide variety of religions until it was no longer politically expedient; then they decided to persecute Christians and declare Zoastrianism as official. When the barbarian hoards from the steppes started to overrun both the Roman and Persian Empires, they decided to cooperate–a huge change–and actually built a wall between the Black and Caspian Seas to stop the uncivilized. Roman soldiers guarded the wall. This helped Rome little, however, because the Visigoths sacked Rome. The barbarians won.
And then there was Constantine’s Counsel of Nicea, held in 410, 420, 424. The “eastern” bishops were not invited. Therefore, the results applied only to what later became known as Roman Catholicism. Infighting among bishops, arguments over who was right and wrong continued, and on and on. Eastern bishops saw the western teachings as heresy. The arguments mainly centered on the divinity, or lack thereof, of Jesus.
The western church focused on rooting out unofficial religious views, while the east focused on missionary activity. The king of Yemen even became a Christian. Rulers converted, shifted allegiances, persecuted or tolerated, according to political expediency.
Little seems to have changed in 1500 years.