QUESTION: Our son has been on a spiritual search for several years but he has just dropped a bombshell. He wants to convert to Christianity and we don’t know how to persuade him not to.

Rabbi Naftali Brawer Naftali Brawer is rabbi at Borehamwood and Elstree United Synagogue.

It must be extremely painful to learn that your son wants to exchange his faith for Christianity. However, all is not lost.

The story is told of a bright young Russian melamed (school teacher) from Kherson, who shocked his family by converting to Eastern Orthodoxy. Years later he became a famous professor of Semitic languages at the University of St Petersburg. When he was asked if he converted out of conviction or expediency, he replied: “Out of conviction, of course. I was convinced that it would be better to be a famous professor of Semitic languages in St Petersburg than a poor forgotten melamed in Kherson.”

Shameful as the story is, it highlights a certain truth; that while it was rare for a Jew to exchange his faith for another, it was even rarer for him to do so out of a sense of genuine conviction.

It would be much easier understanding your son if he chose to abandon faith altogether. However, the idea of exchanging Judaism for Christianity is difficult to grasp in our predominantly secular society, where there are no obvious social or economic benefits to believing in Christ.

I suspect that your son has little knowledge of Judaism and even less knowledge of Christianity.

In 1769, a young Swiss theologian named Johann Kaspar Lavater challenged the Jewish philosopher Moses Mendelssohn to “do what wisdom, the love of truth and honesty must bid him” and renounce his faith for Christianity. Mendelssohn’s purported response was that if the foundations of his house are faulty, he could certainly not be expected to move his family up on to the second storey.

Explain to your son that Judaism is the oldest monotheistic religion and it is on the foundations of Judaism that Christianity rests. If there are theological flaws with the foundation, then the whole structure must be unsound.

Challenge your son to at least make an informed choice before throwing away his birthright. Encourage him to begin living as an observant Jew; praying daily, keeping the Shabbat and studying Torah. Most importantly, find him an intelligent and sensitive mentor whom he can discuss his questions with. There are no guarantees, but I am fairly confident that the more he delves into his own rich faith, the less need he will have to search for spirituality elsewhere.

Rabbi Jonathan Romain Jonathan Romain is rabbi at Maidenhead (Reform) Synagogue.

It is clear that you are deeply concerned. I would feel exactly the same. However, part of me might take a different attitude: that despite my own sadness, I might also be pleased that someone who was obviously a religious person, and who had been involved in a long search, has at last found a spiritual home somewhere. It would not be my choice, but if he was truly happy becoming a Christian, then, with two caveats, I would not try to dissuade him.

The first caveat is that he had not been pressurised by others — be it a partner exerting undue influence or a missionary group deliberately targeting him. Conversion must be voluntary.

The second would be that he had explored Jewish tradition thoroughly before deciding that it had nothing to offer him. If a person has been brought up on a Judaism that was either negative (more don’ts than do’s, only rituals and no ethics or spirituality) or hypocritical (parking round the corner, eating kosher in and treif out) or childish (limited to talking snakes and man-swallowing whales), then it is all too easy to be attracted to another faith that is presented in a more engaging and sophisticated way. Judaism can be immensely enriching — but only if you are exposed to its riches.

It is also worth remembering that rejecting Judaism does not mean that your son is rejecting you. Countless offspring adopt different political stances or have different interests from their parents, but still love them dearly.

You may wish he was not leaving Judaism, but do not confuse that with leaving you. You need to ensure that a religious disagreement does not turn into a family crisis.

Keep the channels of communication open and make sure that, however strong your disapproval, he still feels welcome in your home. It also means that, should he ever wish to return to Judaism, it will be much easier for him to do so.

Be aware, too, that from his point of view, his conversion is probably based on positives — it is not a denial that Judaism has any value, but that he himself is more attracted to features within his new faith, just as some non-Jews admire Judaism and join us. The religious traffic flows in both directions, and just as we accept one way, we have to accept the other, even if it sometimes hurts personally.