Recently I listened carefully to a series of podcasts taken from CBC Radio's Ideas broadcast. I think it was originally produced in 2012, but the podcasts came to my attention only recently. I selected one of these for students of two of my history of religion online courses, one at the University of Guelph and the other at the related institution, the University of Guelph/Humber.
I presented the third podcast because it deals with the very nature of religion, of society and of the relationship between the two. The producer, David Cayley interviews William Cavanaugh a theologian at DePaul University in Chicago. The interview centres around two books of his, one called The Migrations of the Holy (2011), and the other, The Myth of Religious Violence (2009). Generally (and this is a very general statement!), Cavanaugh advances the idea that the new nation-state became and usurped the object of worship from faith in the early modern era. He thinks that 'religion' became both a tool of the new form called the nation-state and a scapegoat for violence from which the State claimed to protect citizens. In reality this was a cover for violence which as is usual in history was a product of greed, honour, the desire for expansion and so on. Later, the state began to find religion less useful and privatization occurred.
I am not sure yet what to think of his ideas, except of course, most wars were not primarily religious, though sometimes religion was a factor or used by those promoting war, and only rarely was religion a prime factor. This is a reasonable stance for any serious student of history to take. Cavanaugh is farther out on a limb when he discusses the role of religion today - citing examples such as the Papacy's opposition to war in Iraq. He sees 'religion' as having a role in a faith an a political sense.
I need to think a lot more about this before coming even to preliminary ideas.