Constantinian Consternation

Rulers make bad lovers,

Better put your kingdom up for sale.

-Fleetwood Mac, Gold Dust Woman

For the first three hundred years of the Common Era, the group of Jesus followers that would eventually become the church were really little more than a curious hybrid of Judaism and Greek philosophy.  The news that Jesus of Nazareth had purportedly been raised from the dead, and ascended into heaven was by no means an earth shattering revelation to most people.  Few outside of the Jewish faith understood the messianic expectation that indwelt Jesus' life and ministry, and as far as Greek thought went, the Logos was old news.  But somehow the faith withstood various persecutions, and even more dangerous times of success, it discerned truth as it walked down a sometimes wandering doctrinal path, which was largely defined by the correction of various gnostic errors.
Quite surprisingly to many, this thing that was being called Christianity was doing rather well.  It was not, however, the "official" religion of anyone or anywhere, and it still had to deal with the odd persecution here or there and the ever-present reality that it didn't have much of a foothold in what many of their Apostles called "the World," in a somewhat adversarial tone.  It was okay though, because followers of Christ were called to be pilgrims and witnesses and a light in the darkness, and they were encouraged by all of Jesus' status-challenging teachings and the dramatic perspective shift of these books they called Gospels, or Good News.
In this period, I'm fairly sure that no one called themselves a follower of Jesus, "just because."  I'm not being idealistic here either, I'm fully aware that this early iteration of Christianity had many issues, most of which are still rather pesky even after almost 2000 years.
But in 312 C.E. the best and worst thing that could have ever happened to the followers of Jesus Christ occurred: Constantine, the man who was about to become Roman Emperor, essentially became a Christian at precisely the moment when he was able to claim authority over the Western Roman Empire, the battle of Milvian Bridge.  Constantine had a vision, and later attributed his victory to God, and faith in Jesus.  Thus one of the more peculiar story arcs of human history came into being: a ruler of the very empire that had crucified Jesus was now a follower of Jesus, sort of.
It is also, probably, the moment where triumphal Christianity became a thing.  I don't imagine that when the Apostle Paul wrote, "Thanks be to God who gives us the victory through our Lord Jesus Christ," that he was thinking of a Roman Emperor winning a battle.  In fact in 1 Cor 15, he's talking mostly about resurrection, which means dying happens as a part of the whole equation, but that's probably an argument for another time.
It's hard to overstate what a massive impact Constantine's conversion and subsequent establishment of Christianity as the "official" faith of the Empire, had on the Church and the world.  It led directly to the creation of the Nicene Creed, which was good, but it also led to the necessity for the Church to become something it was and is perhaps ill equipped to be: a Ruler.
This is a religion founded around a crucified man.  This is a religion that, in it's most authentic expressions, cares deeply for the marginalized and the downtrodden.  This is a religion that has the notion of taking up a cross and dying to yourself at it's very core.  So, while I am always happy to hear about Constantine's conversion, because I'm always glad when people get to know Jesus, I'm coming to think that perhaps it would have been better for us all if he had just tried to live out his own salvation rather than imposing his faith on an entire Empire.
There are, no doubt, times when all of us feel a little frustrated by the insistence of our Constitution that the government remain neutral in matters of religion, but I am convinced that it is really the only way.  I would prefer to live in a religiously neutral country than in a Christian one, or a Muslim one, or a Jewish one, or in any other form of theocracy or religiocracy. I would also argue that since Atheism is technically a religious position, it also shows its flaws in this arena.  The best case scenario is essentially an agnostic, neutral government.
Religions, including Christianity, make bad rulers.  While religious principles and religious people may be important elements in creating a state where justice is valued and equality is a goal, the attempt to run anything like a truly diverse, secular society while privileging one religion over others is doomed to injustice and ultimately will be consumed by brutality.
Do I think that religion should keep it's nose out of politics?  By no means, but the political arena should be a neutral space where the field is not tilted in favor of one group at the expense of another (this goes for economic and racial groups as well).  We have work to do in this regard, and we should do it with some level of urgency, because we cannot really face the dangers imposed by the fearsome Islamist States, without understanding how we as "Christian Nations" have fallen short of the goals of justice and equality ourselves.
As for the dream of an ideal society based on Christian principles, our current doctrine of separation of church and state is probably the best attempt so far at making that a reality.  Is it perfect? No, but it's the best chance we've got.  I want my government to be neutral when it comes to matters of faith, I don't want them telling me what to do or what to say, I don't want them interfering in my walk with God.  My faith will shape my political life, and my place in the community, I want it to be allowed to do so, but I also hope that others will be free to do the same, whether I agree with them or not.