Who founded Christianity? The obvious answer, of course, is Jesus Christ, although this is complicated and misleading: “Christ” was not the last name of Jesus! It simply means “the anointed one” in Greek, christos, and it was applied to Jesus of Nazareth, the wandering Jewish rabbi who is the subject of the four gospels and, crucially, the letters written by Paul of Tarsus, who in his travels throughout the Roman Empire and by his prolific and eloquent correspondence invented Christianity.

That is, there was no theology until Paul came along. (Most scholars agree that only six or seven of the thirteen letters attributed to Paul were actually his; the others were “school of Paul,” and they often work against the radical Paul, subverting his ideas to make the apostle seem more patriarchal and restrictive.) In essence, Paul formulated the key ideas about Christianity that we now take for granted, and he did so on the fly, so to speak—in impromptu sermons and letters.

Paul and his associates (mostly Luke and Timothy) traveled incessantly over several decades, by foot, by ship, on horseback: whatever means were available. They covered rough terrain, often putting themselves at risk. And the record of their journeys, as described by Luke in the Acts of the Apostles, remains one of the thrilling travelogues of all time. These self-appointed missionaries moved through towns and villages in Palestine, in Asia Minor (what is now Turkey), in Cyprus and Greece, in Italy—Rome was always a key goal of Paul’s journey.

Wherever they went, they first met with Jews in the local synagogues, and they also spoke to “gatherings” of those committed to the Way of Jesus, as the movement came to be known. (The Greek word for “gathering” is ekklesia, was later translated into English as “church,” although the word kuriakon, meaning “house” or “Lord’s house” was also used. But it’s important to note there was no early church per se, just a loose association of gatherings, with no rules, no real hierarchy.)

So what on earth did Paul and his friends really preach? How did they manage to create a “church” or did they, in fact, imagine such a thing was either important or possible?

I’ve been struggling with these questions for some years. In fact, I recently recorded Jesus, Paul and the Early Christians—a series of 21 lectures on the early church and its founders, and just published The Damascus Road: A Novel of Saint Paul. The latter is a book I’ve been contemplating for some years.

In a sense, the journey I describe in these lectures and the novel is very a personal one, and it began in the 1950s, when I sat at breakfast with my father, an evangelical Protestant minister. He often read aloud to my sister and me from the letters of Paul and, of course, the gospels, so I knew these texts in the King James Version of the New Testament pretty well by heart by the time I left home. In college and graduate school, I studied Greek, and I began to dig into the original texts: all of the New Testament, of course, was written in a Koine Greek, which is much simpler (with few inflections, less complicated syntax) than Homeric Greek or the Greek used by Plato and Sophocles, for instance.

I’ve spent the past 50 years thinking about the figure of Jesus, his message to the world, and what it means to pursue “salvation”—a very bad translation of the Greek soteria. In my view, a better translation would be “wholeness” or “safety” or—even better—”enlightenment.” Jesus talked about a gradually unfolding kingdom, and when asked pointedly where this kingdom would be found, he said: “The Kingdom of God is within you.” (Luke 17:21)

This is astonishing. The whole universe of enlightenment will be found within the individual psyche, or soul (which is a translation of that word). The Christian message is, in effect, a message of reconciliation between the individual and the universe itself, or the governing principle of the universe, as contained in that wonderful Greek word logos, which is translated in the King James Version as “the Word,” as in: “In the beginning was the Word,” the opening of the Gospel of John.

After a period of three years in the desert, for contemplation, he took up the job of spreading Christianity through the known universe by whatever means necessary.

Paul of Tarsus was an exact contemporary of Jesus. After growing up in Cilicia (Turkey), he studied in Jerusalem under the grandson of Hillel, a teacher called Gamaliel. He became a Pharisee—one of the sects of Judaism devoted to the letter of the Law of Moses. He allied himself with the Jewish Temple elite, worshiping regularly at this magnificent building that Herod the Great had restored at huge expense. As one can tell from Paul’s letters, he was a superbly well-educated and articulate man, and his presence would have been felt within the community.

While on the road to Damascus to root out those associated with the Way of Jesus—a tiny cult that in his view threatened disorder, which was not a good thing in Roman-occupied Palestine—he experienced a dramatic conversation in the form of a vision. He was “turned around,” as they say. He was apparently blinded by the light, then his sight was restored: a metaphor with literal meaning. After a period of three years in the desert, for contemplation, he took up the job of spreading Christianity through the known universe by whatever means necessary. And he did so with legendary success.

His eloquence and learning were his main assets, recognized by everyone who met him. The proof is in the pudding: he managed to establish “gatherings” throughout the empire, creating a network of loosely associated followers of Jesus. And this network eventually overtook the pagan world. By the early fourth century, Christianity had become the official religion of the empire, a development nobody at the time of Jesus or Paul could have imagined.

But what was Paul’s main idea? In my view, it will be found in his letter to the Philippians, in the second chapter. This is my translation:

Jesus, though one with the spirit of God,

had no wish to use his oneness with God as something for his own advantage;

instead, he made himself nothing

by assuming the role of a servant,

taking on human likeness.

And so becoming flesh and blood like a man,

he humbled himself

by submitting to the process of death—

even death on a cross!

It’s a poem in itself, which is why I separate it here as such. The process of self-emptying, in Paul’s Greek, is kenosis. And it’s the point of the cross, the point of Easter.

Paul was a radical thinker, and there are many correlations here with Hindu and Buddhist thought: the idea of emptying oneself out, losing one’s “little” selves to unite with a larger Self is central to understanding his theology. Of course, as an educated man who had studied Greek philosophy and literature, Paul would also have known Plato (whom he quotes now and then, in passing), and so much of his writing and thinking emanates from that source and the traditions of Greek philosophy. Like all great thinkers, he had a synthetic mind.

I’ve tried, in The Damascus Road, to get into Paul’s head, this crazy, wild visionary who invented Christianity. But I’ve tempered the often ecstatic motions of his thought by countering his vision with that of Luke, his longtime companion and, indeed, his biographer. Luke was a quiet and sensible man, by comparison to Paul. He took on Paul with a deep breath, patiently chronicling his advance through the Roman world, his limited sense of self-preservation, his daring-do, his insane courage in the face of obvious threats to himself and his community.

Without Paul, there would be no Christianity. The Way of Jesus would have shriveled into a tiny sect in Jerusalem, led by James, the brother of Jesus, who had none of the charisma or elocution we associate with Paul. It would have disappeared within decades, I suspect. But Paul opened the idea of a new heaven and a new earth—the Christian vision of God’s kingdom—to the Gentile or Greek world, and that made all the difference.