The word olio survives in English usage, I suspect, because the New York Times crossword puzzle frequently resorts to using it when it needs three vowels, but not using an “e” as in the similarly-spelled synonym for margarine. The original olio was an Iberian stew consisting of “whatever’s around,” and thus today the word refers to any collection of barely related items.
Fish don’t know that they are in water, and most American Christians have no idea of the “olio,” or as my former British co-workers would say, “the bits and the bobs,” that make up their religious tradition.  This is most evident in today’s Fundamentalist theological strand, whose adherents (and the mainstream media to a large extent) frequently assume that the very word “Christian” is synonymous with “Fundamentalist” or “Evangelical.”
The one book that most influenced my study of ethics during the 1990s was the narrative of a course taught for many years at Union Theological Seminary and Harvard Divinity School by the legendary theologian Paul Tillich. This text, called A History of Christian Thought, is a chronology of the evolution of over 1900 years of Christian doctrine and dogma, paralleled by a sociological history of the world in which those theological innovations emerged.  I characterize this book as a “chicken-egg” contest of “Who influenced whom?” with the societal and political innovations of each period usually winning the contest. Christianity has long been malleable to leaders and dominant culture.
The olio started early
Most Christians think that “their church” started with Jesus, but much, perhaps most, of the story begins with Paul of Tarsus introducing this Jewish prophet to a largely-Hellenist audience decades after his execution. The Hellenists, representing the cities for whom Paul’s epistles are named, occupied what is today mostly Turkey and Greece. They were more culturally Greek than Jewish or Roman, the latter being the political power center. The story of the Virgin Birth of Jesus, for instance, was a theme that inherently “made sense” to the Greeks, who had no problem conceiving of gods procreating with human women, although this was heresy to the Jewish scholars. Indeed, that faith statement was likely required in order to elevate Jesus into “Divine Christ” status. 
The “gotta have it to be called Christian” doctrine of Trinity did not get nailed down until the Nicene Creed emerged in the 4th century CE, and its creation was very much tied to the political alliance of the Church with Emperor Constantine. And as Paul Tillich points out, that creed famously incorporates Greek natural philosophy about the nature of “substances” from which all things, including gods, are made. 
Finland’s capital of Helsinki demonstrates well yet today the near-Darwinian divergence, both sociological and doctrinal, of Christianity between East and West lasting for 1000 years after the big split at the end of the first millennium CE. Then came the cultural clash when the occupying Swedish Lutherans met their replacement Orthodox Russians who took control over Finland in the early 19th century. These two strands of Christianity are now very different “species” and can likely no longer interbreed.
Less than 500 meters apart, the Orthodox Uspenski Cathedral is dark and icon-heavy, while the Lutheran Helsinki Cathedral is bright white and green, both inside and outside, with few adornments inside beyond a marvelous pipe organ. Their theologies, especially in this twenty-first century, are similarly in high contrast, and yet both label themselves “Christian.”
Crossing the waters
I have often joked that my own demeanor is “genetically Lutheran” even though I have never been a member of that denomination. It gets very hard to separate the emerging Northern European culture during Martin Luther’s and John Calvin’s 16th century from the theological innovations of Protestantism. And its further sub-divisions (and, I argue, literal DNA) were clearly shaped by emerging national identities. The broad cultural and theological differences between German Lutherans and Swedish Lutherans, for instance, remain today, both in their home countries and in immigrant America. Missouri Synod Lutherans, emerging from the more conservative, Biblically-literalist German strand, and ELCA Lutherans, mostly rooted in Scandinavian traditions and 1960s-era aggregation, agree on very little, either theologically or politically.
In the migration to America, Christianity picked up a strong, often ugly, Manifest Destiny theological strand that just does not exist in European counterparts to the same denominations. The Latter Day Saint movement was especially grounded in this doctrine, but the 20th century’s emerging Dominionism theology in Evangelical Christianity, where religious dogma must be made into law, and then administered only by right-wing Christians, puts a particularly American political spin on conservative Christianity.
Emerging from enforced Christian conversion all the while they were enslaved, the Black church in America found its inspiration in the Old Testament stories of Moses escaping slavery, and in the counter-cultural “liberation” from oppressing rulers and their allied religious authorities found in the gospels and the experiences of the early apostles recorded in the book of Acts. While there is a current political movement to silence the discussion of Christian oppression of ethnic minorities and aboriginal Americans in our history, this story needs to be told to our children as well. It has largely survived as a part of that always-changing “olio” of American Christianity, but “liberation theology” is still often characterized as a threat to white Christianity.
The ethic versus the dogma
Lost in much of this dogmatic evolution is the patently-clear early Christian ethic, especially detailed in the gospel of Matthew, chapters 5, 6, and 25. The Jesus of that scripture preached personal sacrifice, peacemaking, the worth of all persons, and our collective responsibility for “the least of these,” a far cry from the emphasis of much of the Christian church today.
I admit to having my own personal theological “olio,” and you likely have it as well, even if you are a non-believer, and even if you don’t name it. In addition to the above “Jesus ethic,” the Greek Fates teach me something about the probabilistic randomness in which we are born, live and die; the theology fits the data. The Buddhist concepts of dukkha and impermanence remind me of the fragility of my life. Finally, the great physicists have taught me about the vast wonders of time and space, and also of my own humble and minuscule part of it.
And yet, in a world of unlimited information in our pocket phones about our olio of religion, we haven’t been able to come together.
“Where is the wisdom we have lost in knowledge?
Where is the knowledge we have lost in information?”
― T.S. Eliot, The Rock
- This fish analogy, usually attributed to Albert Einstein, is most accurately quoted as “What does a fish know about the water in which he swims all his life?” from Einstein’s memoir Out of My Later Years (Citadel, 1956, p. 5).
- Tillich, Paul, and Carl Braaten (ed.), A History of Christian Thought: From its Judaic and Hellenistic Origins to Existentialism (Simon & Schuster, 1972).
- I have long appreciated American novelist and theologian Frederick Buechner’s advice that “life is complicated enough without confusing theology and gynecology.” (Wishful Thinking, p. 94)
- The long debate was primarily over whether God and Jesus were made of “the same substance” (homoousios) or rather of “similar substance” (homoiousios, spelled with only a letter i [iota] different). The former word won the debate.