It could hardly be more be surreal. Here I am discussing the significance of the Lord's Prayer, that most emblematic totem of the Christian liturgy, with the most powerful woman in British Judaism in the magnificent Victorian-Byzantine setting of the West London Synagogue at Marble Arch – church-like in almost every respect, with its pews, pulpit, organ and choir. Add in another irony. It is a reminder that in this coming Easter week, when the pulpits of our great Anglican cathedrals will be filled with bishops in all their patriarchal pomp, that the church which nurtured me has not yet managed to elevate any woman into its ordained hierarchy of the stature of Julia (Baroness) Neuberger, now Senior Rabbi of what is known as the "Cathedral of British Reform Judaism".
This is not the first time over the years that, as a member of the Church of England married into a Jewish family and bringing up my young children in my wife's faith, I have felt compelled to tussle with the ideology of my Christian heritage. Meanwhile, I have become something of an expert in interfaith relations as they are negotiated on the front line of domestic life. I can tell my crosier from my crucifix, while Jewish "Friday Nights" have become a fulcrum of our family week.
But there have been few challenges more demanding than the one I face now. This is the year of my son Edmund's bar mitzvah, when I as his father and Rabbi Julia as his spiritual teacher will accompany him on one of the most important journeys of his life as he becomes a man in the eyes of God on his 13th birthday. Over the next few months, I must prepare to stand with Edmund in the synagogue as he reads in Hebrew his passage from the Torah and becomes bar mitzvah – literally "a son of the Commandment". (Don't say "having" a bar mitzvah – it's not a party for either of us, though we'll be having a knees-up once it's all over.) Most daunting for me will be, according to ancient tradition, to cede moral responsibility for my son and making him answerable for his own actions in the eyes of God.
Emotionally, this is also the Jewish equivalent of "letting go" – the moment that every parent dreads. There will almost certainly be a tear (or three) in my eye, and there will be no Jewish mother in the land more anxious than I. (His own mother, I must place on the record, is entirely cool.) Never mind that Edmund might stumble over his Hebrew, how about his father? I'm learning fast, but how will I perform as a total rookie who never converted? Will I be like the Dad in Jack Rosenthal's famous BBC play Bar Mitzvah Boy, who is so exasperating to his son that the boy decides to decamp?
But ritual, like chicken soup with kreplach, is one of the great comforting aspects of Jewish life. I passed my first test when I brought my heel down, smashing the traditional wine glass with accuracy as we stood under the chuppah for the blessing on our wedding day. Did it signify the destruction of the Temple, the breaking of the hymen or was it simply a symbol that life ain't a bowl of cherries? Who knows? But the general murmur of approval from the family afterwards implied I had at least succeeded in my first rite of passage.
I have performed other key rituals in Edmund's short life – privileged especially to take part in that rarest of Jewish ceremonies, the pidyon ha-ben, where the first-born father of a first-born son "redeems" his offspring – buying him back from God for the sum of five silver coins, according to the Law. It was a profoundly moving experience – a time-shift into the pre-history of Christianity. Luckily I was allowed to keep both the money and the boy. And I just about passed the test at his circumcision by neither fainting nor looking the other way.
Fortunately, I have Rabbi Julia by my side for this new challenge. "The best way for you," she tells me, "is to sit down and have a formal discussion with him. Quite often, if you are the non-Jewish parent of a child who is approaching his bar mitzvah ceremony, something quite interesting happens. There will be some clarity about why you didn't become Jewish and you will learn what he thinks about it. How will he relate to his non-Jewish family? Quite often, you, as the father, will feel a bit different afterwards."
And so what she has predicted is already happening. Edmund and I are busily engaged in the start of many conversations we will have together over the next few months. True, I have not converted. Partly, this is because Jews have no tradition of proselytising and I've never been put under any pressure to do so. (We have solved my father-in-law's worry that I may not be able to be buried alongside my wife in a Jewish cemetery – the answer is, I can.) But there has been another nagging, and more atavistic reason – which always sounds feeble when articulated, but is nevertheless true. From knee-high in Sunday school, it was drilled into me that Jesus would always be "my friend". And could you ever turn your back on your best friend?
Luckily, Edmund – with the characteristic lack of sentimentality of every 12-year-old boy – is immune to any kind of schmaltz and tells me that he enjoys our twin traditions – similar in many ways, as he sees it, but also profoundly separate. In return, I shall tell my son about the blessings that Judaism has brought me. Most important is a sense of the warmth and inclusivity that is a keynote of Jewish community life – in contrast to the cold, grey and over-formal world of high church Anglicanism in which I grew up. Even the Orthodox Jews in our family, who frown on intermarriage and who would never have allowed me to marry into their own branch of the faith, have never been less than welcoming to me as "one of their own".
I've also learned to reinterpret Jesus through a Jewish prism. Reading Jewish scholars of Christianity, such as the late Géza Vermes, he no longer seems to be the model Anglican gentleman, eternally "meek and mild", who I grew up with in the sugary world of suburban Sunday school. Instead, here is a passionate Jewish teacher and leader who was very much part of the historical context of his time. Was he the Son of God? Well, at least we can review the evidence. Debate is at the heart of Jewish life.
The same is true of Edmund's Torah reading – the tale of Cain and Abel, one of the classic Bible stories. For me it has always seemed a stern, simplistic Victorian-style homily. But viewed through the interpretations of the rabbis down the ages the symbolism of this account of the first man to be born and the first to die can be understood with infinitely more subtlety. By contrast, I have been forced to confront the shaming undertone of anti-semitism in much traditional Christianity. I couldn't quite rejoice in the recent celebration of the 350th anniversary of the Book of Common Prayer, long one of my favourite works of literature, since I couldn't forget that line from the Collects: "Have mercy upon all Jews, Turks, infidels and heretics and take from them all ignorance, hardness of heart…"
But the main joy of engagement with Judaism has been to turn up the volume on aspects of the Judaeo-Christian life still cherished in the Jewish tradition but which have become muted in our own. One might think of the premium on family life, respect for the elderly, kindness to strangers, philanthropy and charity among many things that Jews do better than us. Young people in our son's synagogue are busy raising money and collecting clothes for victims of the war in Syria – even though every one of the once-large Jewish population of that country has been expunged over the years. Reconciliation and forgiveness are at the heart of Judaism.
Which brings us back to the Lord's Prayer. "How can it be," Edmund asks his rabbi, "that since Jesus and his disciples were Jewish, the Lord's Prayer is not prayed in synagogues?" "A good question," says Julia. "There's absolutely no reason why not. But since it was taken over by Christians, we've rather dropped it in favour of the amidah [the traditional prayer uttered at every Jewish service]. But I go along with it whenever I go to a Christian ceremony. I've even prayed it in Westminster Abbey."
A version of this article originally appeared in 'The Tablet' magazine