If political leaders should steer clear of religion, as Alastair Campbell famously advised Tony Blair, religious leaders should also be wary of politics.
This week's Papal visit to Israel and the Palestinian territories is a case in point.
Since Pope Benedict was elected in 2005, the Vatican's relations with both the Jewish and Muslim communities worldwide have come under strain.
For the Pope to make the visit a success he needs to have addressed three sensitive themes in Catholic-Jewish relations.
First, on arrival in Israel on Monday, he spoke about the resilience of anti-Semitism through the ages, and he must continue to show that he understands the pervasiveness and nature of modern anti-Semitism.
In historic terms it was the Church that promoted the ‘blood libel’, whereby Jews were accused of drinking the blood of Christian children; this led to the caustic remark of the Catholic writer Edward Keating: “We have been guilty of anti-Semitism for 2,000 years. Forgive us.” However, modern anti-Semitism comes from a toxic combination of the far-right, the new left and political Islamism.
A second area of Catholic-Jewish dialogue where trust needs to be built is on the Holocaust. This follows the recent furore caused by the decision to lift the excommunication of Richard Williamson, the Holocaust-denying bishop.
It was unfortunate that the Pope's visit on Monday to the Holocaust Memorial Yad Vashem in Jerusalem, was sidetracked by confusion over the Pope's membership of the Hitler Youth.
In previous pronouncements on the Holocaust he has been reluctant to acknowledge a link between historic Church-based religious anti-Semitism and Nazi racial anti-Semitism.
Of course the Church did not carry out the Holocaust but centuries of demonising and persecuting Jews, at the very least, weakened Europe's immune system.
The specific and extremely delicate Holocaust-related issue in the Papal in-tray is the move to canonise Pius XII, the war-time Pope, whose record has been the subject of such historical dispute.
A third area to address is on theological relations.
The Pope has already signalled on the trip that he remains committed to the Second Vatican Council (1962-65), which charted a path of mutual understanding between the Vatican and others faiths.
But he must ensure that his decisions match up to this laudable goal. His alteration of the wording of the Good Friday Prayer, which calls for the conversion of Jews, caused alarm and more generally, in theological areas, he has shown little inclination to make space for Judaism (or other faiths).
As well as strengthening Catholic-Jewish relations, the Pope has been trying to re-establish trust and bolster links with Muslims too.
In Jordan on Sunday, he addressed King Abdullah and Muslim leaders, with the elephant in the room being the global controversy aroused by his Regensburg address in September 2006.
Pope Benedict has endured a difficult, at times turbulent, four years since taking up the Papacy. If his visit is a diplomatic and inter-faith success it can help restore relations with the Jewish and Muslim communities and get things back on the right track.
Zaki Cooper is a trustee of the Council of Christians and Jews, and writes in a personal capacity