In recent years there has been a great deal of progress in Christian-Muslim relations. Of course there are significant tensions between the world's two largest faiths in some parts of the world, with the religious freedom of Christian minorities in many Muslim states under the microscope. Nevertheless, since 2006 a series of positive gestures and steps have been taken.

In January 2006, the Archbishop of Canterbury launched the Christian-Muslim Forum. Later that year, the Pope's visit to represented a master-class in diplomatic relations, following the ill-feeling caused by his infamous lecture two months earlier. This was followed in the autumn of 2007, by the high-profile move of 130 Muslim scholars who wrote to the Pope and other Christian leaders urging further understanding between the religions.

Against this background of enhanced faith-based diplomacy, the issue of Turkish membership of the EU has been boiling away. Turkey was officially recognised as a candidate for membership in 1999 and opened its accession negotiations with the EU in October 2005. The country, with its 97% Muslim population, has harboured European ambitions for decades. Indeed it has been an associate member of the EU and its predecessors since 1964.

However, not everyone is enamoured by the prospect of Turkish membership.

The issue has split Europe. Many in the UK have been suppotive of Turkey's membership, and the accession talks were launched as a result of the British government's push in 2005. On the other hand, British public opinion has been less enthusiastic, as the issue of Turkish accession has become linked to migration concerns. Elsewhere in Europe, leaders have been less keen than British politicians. French President Nicolas Sarkozy has been outspoken in his opposition to Turkey's full membership, as has Anegla Merkel, the German Chancellor. Their reservations are surpassed by other member states, in particular Austria, which tried to block the accession talks and where the climate of opinion is implacably against Turkey's membership.

The issues around Turkish membership are extremely complex. There is the dispute over Cyrpus, human rights issues, including treatment of the Kurds, and Turkey's position on the Armenian genocide, to name three leading issues. All these will need to be dealt with in the talks, which will conclude by 2014 at the earliest and probably much later.

However, notwithstanding these serious obstacles, there are strong arguments for Turkey's membership. The move would boost the EU's single market, and the country's relatively youthful profile (23% of population is under 15) could help to counter the demographic problems that faces. Second, in the age of geopolitical instability, Turkey's accession would provide the EU and the West with an important strategic ally, with a border to the Middle East. Third, the process of EU membership negotiations has already encouraged democratic reforms in and should continue to do so. Examples are the abolition of the death penalty, and the recent vote by the Turkish parliament to modify its law making it harder to prosecute people for "insulting Turkishness".

In addition to these economic, strategic and democratic advantages, perhaps the largest benefit resulting from Turkey's EU membership would be to bring Islam and the West closer together. It would show that Muslim (majority) and Christian states can work well together in harmony. Turkey would serve as an example to other Muslim states who are interested in enhancing cooperation with non-Muslim states.

Some are nervous about including a country of 70 million Muslims in the EU. They tend to associate European identity with Christianity. They worry about the rise of a large Muslim minority in the EU. Some commentators take the argument further, anxious that the continent will be overrun by an assertive Muslim minority.

But those who are sceptical of Turkish membership on religious grounds have some major drawbacks in their arguments. First, the EU, when it was formed over fifty years ago, was not established as a Christian club, but as an attempt by nation states to cooperate on common issues and challenges. Second, Turks regard their state as a secular one; the secular republic has more in common with a state like France than the theocracy of Iran. Third, Europe already has a substantial Muslim minority, numbering 15-20 million people, so the issue of a Muslim minority living amongst a non-Muslim majority is already a live one, and one that the EU is addressing.

As we move more deeply into this "age of identity" and people all over the world increasingly identify with religious faith, the quality of the relations between the major religions will be of critical importance. In that context, Christian-Muslim relations is key. Turkish membership of the EU would provide a boost to the relationship and to Western-Muslim relations more generally. Our political leaders must seize the opportunity to keep the door open to Turkey, and when they are ready to welcome them in to the European household.

Zaki Cooper is a Consultant to the Cambridge Inter-faith programme, a Trustee of the Council of Christians and Jews and the Director of Business for New Europe.