Geza Vermes, one of the great scholars of the Dead Sea Scrolls, changed accepted views of the life of Christ. Now he has written his own life: the story of a Jew who converted to Catholicism to survive the Holocaust, became a priest, and has now reaffirmed his Jewishness. By Paul Vallely
he cottage stood on the edge of a 600-acre wood of broad-limbed oaks, down a lane enclosed by high beech hedges. A scholar's idyll: semi-rural, tranquil yet within reach of the libraries of Oxford. While its owner was making coffee, I surveyed a room lined with hardback books. There was a gargoyle carved into the antique beam over the fireplace, and comfortable, well-worn furniture. Then, in one of those eerie moments when time wilfully re-orders itself, I was hurled into a world in which all this did not exist and in which Geza Vermes, Oxford's Emeritus Professor of Jewish Studies, did indeed perish with his relatives when Hitler's Holocaust finally swept through Hungary in 1944. The room was empty, the furniture gone. The sensation lasted only for a moment and then history reasserted itself. In through the old door came the professor, his hairline receding and his beard flecked with grey.

Geza Vermes has lived in this country for more than 40 years but he still looks an emigre in his blue slacks, green-checked sports jacket, dark turquoise suede waistcoat and yellow tie. He set the coffee down by a table on which was neatly piled his manuscript for the forthcoming Volume 26 of The Discoveries in the Judean Desert, the Oxford University Press edition of the Dead Sea Scrolls (the controversial collection of manuscripts discovered in caves near the Dead Sea in the Forties and Fifties which throws new light on the Bible story), of which Vermes has for decades been this country's most formidable student. More significantly, perhaps, he was the academic who 25 years ago rescued Jesus from Christianity and reminded the world that the founder of the world's biggest religion was himself, actually, Jewish. It seems an odd thing to say now. But the publication almost three decades ago of his Jesus the Jew - the first of a trilogy of seminal works that set out to disentangle the historical Jesus from the theology and legend that subsequently enmeshed him - came as a revelation to the Christian world. It caused many inside and outside the churches to re-evaluate their understanding of the figure at the heart of Christianity. This was a shift summed up in the definition of Jesus in the Oxford English Dictionary, which BV (Before Vermes) was "the name of the founder of Christianity" but which was, AV, transmuted on his advice to "the central figure of the Christian faith, a Jewish preacher (c5BC-cAD30) regarded by his followers as the son of God and God incarnate". As the Anglican apostate A N Wilson put it, once one had absorbed the message of Vermes's books it was impossible to view Christianity in the same light ever again.

Vermes's scholarship gained purchase from his own singular life. He was born a Jew, converted to Christianity, became a Catholic priest, and then 20 years later reconverted and re-affirmed himself as a Jew. More than that, in his remarkable spiritual wanderings can be detected a kind of index to the progress of Jewish-Christian relations throughout the 20th century. The crucible of which was, of course, the horror of the Holocaust, a word which, it is nowadays often forgotten, literally means sacrifice. That others were sacrificed, and he was not, was clearly an experience that changed him irrevocably. "Going through that," he says, "brings you to the realisation that you shouldn't have survived and that, if you have, that must have a purpose - and you have a duty to do your best to fulfill that purpose. I have never felt that I should be ashamed to be alive, but I have felt that survival was a privilege that conferred duty. I have felt more and more that I had a duty towards Jews and Judaism. It was the one area, I suppose, in which I felt qualified to make a real contribution."

Vermes was born into a Jewish family that converted to Christianity when he was not quite seven. The move was largely for social reasons, though his mother became reasonably pious in her new faith. They became Catholics, though he remembers the joke at the time was that Jews converted to become Protestants first and then later switched to Catholicism: "This was so that when they came across a form which asked for their 'Previous Religion' they would have something safe to put." But there was little safety in conversion. When he was 16, the third of a series of anti-Jewish laws were passed which defined Jewishness on a racial basis rather than by religious affiliation. The boys in his school staged a boycott of their three Jewish classmates.

This month, Vermes has published his autobiography, Providential Accidents. It is a curiously emotionless book which records events and seems to pass over the truths lodged in the interstices between the facts. The boycott was a traumatic event: "It was only 50 years later that I really got over it when I returned to the school," he says. When I press him on it, his careful grammarian's sentences break down. "The arbitrariness," he says. "It was something totally unjust." Yet it did not shift him from his acquired faith. Vermes determined to become a Catholic priest. But even from the start the ambiguity of his position was evident. As part of his theological training he had to learn Hebrew. "I see you are busy now with what you should have been doing as a child," one of his uncles said, coming across him engrossed in a grammar.

Vermes was a priest for six years, but his immersion in Hebrew led him into scholarship rather than to service in a parish. It was perhaps just as well, for after working in Paris and Jerusalem he paid a visit to England where he met and fell in love with a married woman. "I was a pious young man in those days," he recalls, "but in what I would call today a very primitive way. Religion as an intellectual problem played no part. You just accepted things and did what you were supposed to. Suddenly, after I met Pam, I had to face things myself and make decisions." She left her husband and married Vermes. The couple were both rejected by his church and, though for a while they continued to attend Catholic services, they soon drifted away. It was at Newcastle University, where he obtained a post in the philosophy department, that he was reacquainted with Judaism through a number of his night-school pupils who were Jewish. That process accelerated when he took up the post of Reader in Jewish Studies at Oxford, where he has remained ever since. Five years later, in 1970, he made a public redeclaration of his Jewishness. "There was no dramatic conversion. I did not deliberately move from A to B, from Christianity to Judaism. All these events were followed by a quiet internal development at the end of which I simply found that the previous situation felt strange to me. I did not leave Christianity, but imperceptibly grew out of it."

He was not inclined to embrace Judaism in its conventional form. Organised religion of any description no longer suited him at all. "I was confused, but chose the only option possible: that of personal, internal prayer without accompanying social manifestations. It was the culmination of a long pilgrimage, trying to find answers to problems as they arose, basically from the Jewish Bible, which contains a number of particularly profound insights."

So in what, after such a pilgrimage, did he locate his Jewishness? "It's an existential disposition towards everything. It's not strictly intellectual. It's having an awareness that you have a role to play and that if you don't play it something important won't happen. I believe that if there is a God, God doesn't act directly but through people - and if people refuse to play their part, then God's purpose won't happen." That, I say, doesn't sound particularly Jewish. It is a definition that could apply in many religious traditions. Is his sense of Jewishness more cultural? "Perhaps." I recall how, at a dinner party in New York, I was once reproved for asking why so many psychoanalysts were Jewish; this, I had been told, was an anti-Semitic question. Is it? "No. Judaism, for example, produces more musicians and fewer painters and sculptors; this is because for a long time Jews were not supposed to produce figurative representations of human beings. You might ask why so many of the greatest composers are Germans. There are certain gifts associated with certain groups and cultures."

He falls silent. What about that "if"? "You said, 'if there is a God'," I remind him. "Does God exist?" "I think he does. But not the God of religion and rite, just" - he reaches for the autobiography and turns directly to a page and reads - "that of the still, small voice which those who listen can hear, as did the prophet Elijah, the voice of an existential God, acting in and through people, who stood behind all the providential accidents of my life." Yet that God, divorced from rite and religion, is a God of solipsism rather than a God of people worshipping together in community. "For a lot of people, what I am saying, I know, doesn't make sense. But it does for me. Even so, I wouldn't consider myself as reneging on my views if I decided one day to become a regular worshipper in a synagogue." Or a church? "Not a church, because I have reached the point in my views which would prevent me from embracing a community which is based on traditional views of the divinity of Christ, redemption, the Holy Trinity and the like."

But the journey has not just been his own. "Over the same period the changes in relations between Christians and Jews are almost unbelievable. On the Christian side, most churches have faced up to the traditional anti-Judaism of at least 10 centuries. The Vatican Council made a tremendous difference: the Pontifical Biblical Commission has since acknowledged the Catholic Church's need to take seriously the work of Jewish scholars. On the Jewish side, the old taboo about not even allowing the name of Jesus to pass their lips has been declared absurd. So has the idea that Jesus was somehow not Jewish or that he was in some way responsible for the centuries of nastiness which followed."

From the vantage point of the present we can look back on the stances of our forefathers with incredulity, but how did Vermes look back on the young self who bridged such a gap? "I look back on that young man with some surprise, but I think that that pious young seminarian in the 1940s was trying to be honest - just as when I ceased to think that way, I was being honest, too. What I was in search of was the truth. What is truth - and how does this truth affect your life? It is the question for all of us"

"Providential Accidents" by Geza Vermes is published by SCM Press