I believe with all my heart that responsible men and women must work to restore mutual respect between faiths, and that we should do all we can to overcome the distrust that poisons so many people's lives.

Your Excellencies, Ladies and Gentlemen, I have been enormously touched that you should have considered inviting me to speak at this most venerable and ancient place of worship and learning. You have done me the greatest honour through your invitation, and indeed through conferring this much treasured honorary doctorate on me, and I count it a very special privilege to visit the University of Al Azhar and, indeed, to return to Egypt – a country for which I have a particular affection and which, for many, has a sacred significance as the place of refuge for the child Jesus.

I would like to begin by paying tribute to the man who first encouraged me to accept the invitation to speak here, a dear friend and graduate of this great university, Shaikh Zaki Badawi. His sudden death in January was a profound shock and an immense sadness to many of us across the world. He was a man of real wisdom and learning. With the humility of a true scholar, he made his great knowledge accessible to others – and did so with an irresistible sense of humour. I am so pleased and proud that his widow Lady Badawi is with us for this occasion.

I do not claim to be a scholar, other than having studied history at the University of Cambridge – not quite as old as this one, but I do have a great interest in exploring the Abrahamic tradition into which I was born. This tradition has shaped me and made me who I am. Today I stand before you as one belonging to the family of faiths connected by that tradition.

The roots of the faith that we share in the One God, the God of Abraham, give us enduring values. We need the courage to speak of them and affirm them again and again to a world troubled by change and dissension. That is the message which, above all, I wish to leave you with today. First, and highest among those values of our common inheritance, and born of our love of God, must always come respect for each other, and for His creation. Our respect for all God's creatures and for the environment is the expression of our respect for the Creator whose inspiration is the entire manifest world.

Secondly, and following from this, our beliefs and values call out for peace and not conflict. We may have a human weakness to criticise and to compete with each other. But what we have in common, as people of faith, calls us beyond this towards mutual respect and understanding.

Thirdly, the great Abrahamic traditions speak of a faith which rests in the heart beyond the limitations of our intellectual knowledge and judgement. Wherever we are placed in our human society, whatever the advantages or disadvantages we have in ability or education, we perceive the truths of our faith with the ‘eye of the heart'. The Prophet Moses reminded us that the heart is the seat of faith: “Thou shalt love the Lord thy God with all thine heart” (Deuteronomy 6:4). I believe that the great faiths speak through their sacred texts to the heart, and that faith itself is heart-felt.

But while I cherish the connections within the history of our different Abrahamic Faiths, I do not want you to imagine for one moment that I think that they are one and the same. There are differences, and we should celebrate them. But in the things that matter most, we have a common root. In my view, God's purpose should never be in doubt: it is to bind us closer together! Unity through diversity… Indeed, it has always moved me that the Holy Koran has a verse: “O Mankind! We created you from a single pair of a male and a female, and made you into nations and tribes, that ye may know each other (not that ye may despise each other).”

I first voiced my thoughts publicly on relations between Islam and the West in 1993, in a speech at another great university, Oxford. Something I said then has troubled me ever since. I said:

"…despite the advances in technology and mass communication in the second half of the twentieth century, despite mass travel and the intermingling of races…misunderstandings between Islam and the West continue. Indeed they may be growing."

Tragically, the intervening twelve years have confirmed my fears and, for so many, those years have been profoundly bleak. My heart is heavy from witnessing the never-ending death and destruction – the kind of death and destruction I understand only too well, having experienced the loss of my beloved Great Uncle, Lord Mountbatten, at the hands of terrorist bombers in 1979. Images of communities torn apart by religious conflict are deeply harrowing – from Bosnia to Baghdad, from Chechnya to Palestine – evidence of just how far misunderstandings have continued and escalated. Violence, so often justified in the name of religion, effects a terrible hardening of hearts. What good can possibly come of all of this?

In that same speech, I talked about the history of Europe and the Islamic world – how they were inextricably entwined, and how, through the centuries, the giving and taking on both sides had contributed so greatly to what we have become today. History shows what giant leaps of creativity in knowledge – in science, literature and the arts – have occurred when the members of the Abrahamic family have worked together.

Can we not draw inspiration from the great explosion of knowledge and understanding which took place under the Abbassids between the ninth and thirteenth centuries, when their capital Baghdad was a world centre of learning; or from Islamic Spain between the tenth and the fourteenth centuries, when in cities such as Cordoba and Toledo, the work of Christian, Muslim and Jewish scholars led to the flowering of the Renaissance? We need to remember that we in the West are in debt to the scholars of Islam, for it was thanks to them that during the Dark Ages in Europe the treasures of classical learning were kept alive.

But in that same speech I also spoke of how, sadly, despite this fertile flow of ideas, many on both sides had still been left with uncompromising prejudices towards each other's cultures. This lingering mutual distrust persists, and with dreadful results. I think of the experience of Muslims living in Europe who are subject to varied and continuous expressions of Islamophobia by fellow-Europeans. I think of Christians living within some Muslim nations, who find themselves fettered by harsh and degrading restrictions, or subject to abuse by some of their fellow-citizens. And I think of dreadful acts of terrorism and violence across the world, carried out in the distorted name of faith.

I believe with all my heart that responsible men and women must work to restore mutual respect between faiths, and that we should do all we can to overcome the distrust that poisons so many people's lives.

This, of course, is made infinitely more difficult by the stereotypes and absurdities propagated by certain sections of the Media. In my own very modest way, through the work of my Prince's Trust, my Foundation for the Built Environment and my School of Traditional Arts, I have sought to find ways to integrate communities and to celebrate the virtues of Islamic cultures in the United Kingdom.

As these programmes develop across other countries, I hope that they may serve as a model for communities elsewhere. Even from small projects and examples the foundations of mutual respect, consideration and courtesy can be rebuilt, sometimes through the physical design of people's surroundings – surroundings which can help to enhance our shared humanity rather than treat us as technological adjuncts to the increasingly mechanistic world around us.

The legacy of misunderstanding and conflict between religions has had a central role in the terrible history of war and violence. And none more so, of course, than the truly apocalyptic cruelty and destruction caused by the two unholy, secular “religions” of Communism and Fascism.

Over the centuries, as societies have evolved, we can often see two distinct reactions to this ruinous legacy. Some hold ever more tightly to their religion, as a source of stability in their lives – and, as conflicts rage, they identify other traditions only as threats. Others become disenchanted with religion altogether; with the whole concept of metaphysics and a dimension beyond ourselves. They abandon any faith in God, and see religion itself as “backward,” “primitive” and “wrong”. This disenchantment and indifference poses a danger for our inheritance of faith, universal values and a living tradition. Coupled with an obsession with materialism and trivia, it is a threat across the world, not least to our own traditional Christian culture.

In Europe, it was partly in reaction to the apparently ceaseless wars between different Christian denominations that many sincere people came to think that if we could only create truly secular societies in which the bigotry, violence and pedantry that people associated with religion would disappear, the underlying sources of conflict would be removed, and we would all get on better. They hoped that if, in the place of institutionalized religion, the material wellbeing and security of the people could be enhanced and protected through the discoveries of science, then the march to harmony, progress and human happiness would continue unopposed.

Inevitably, it has not turned out to be quite so easy. As we are finding, scientific knowledge, which has brought us all so much that we value and are privileged to take for granted, is not the same as Wisdom. For it is Wisdom alone that can reveal to us those universal and eternal truths that lie at the heart of all the great traditions. In many people's lives today these truths, which provided our forefathers with a secure framework for their existence and with a clear set of ethical values, have become obscured, have disappeared entirely from their lives. This is not a phenomenon peculiar to the West. We see it in each strand of the Abrahamic faiths.

The implications of this loss run deep. For I believe that moderation comes from the Wisdom passed down to us through tradition. Extremism exploits our loss of respect for tradition. Loss of religious certainty is pushing many to take refuge in new absolutes which, like any primitive belief, tolerate no doubt or reservation, but lead to various forms of extremism.

We need to recover the depth, the subtlety, the generosity of imagination, the respect for Wisdom that so marked Islam in its great ages. Islam called Jews and Christians the peoples of the book, because they, like Muslims are a part of a religion of sacred texts: the Koran, the Hebrew Bible, the New Testament. And what was so distinctive of the great ages of faith was that they understood that, as well as sacred texts, there is the art of interpretation of sacred texts – and this is a difficult and subtle art that gave rise in Islam to great principles of interpretation and great schools of jurisprudence.

Between the text and the meaning of the text – between the meaning of God's word for all time and its meaning for this time – falls the act of interpretation. It was Islam's greatness to understand this in its full depth and challenge. And this is what you, at this great and historic institution, can give not only to Islam, but, by example, to all the other children of Abraham.

Today, too often, there seems to be a tendency to read texts as if they needed no interpretation, as if we could read their meaning on the surface. That does violence to the Divine word, and violence to the word eventually leads to violence to the person, and to the world.

When all we can hear in sacred texts is simple certainties, when all we can see in God's multicoloured world is black and white, we begin to divide humanity into simple oppositions: the good and the evil; the pious and the profane; us and the enemy. And this then leads to hatred and violence. For it is then that we lose the single most important principle that unites the Abrahamic faiths: in Judaism, “Love your neighbour as yourself” (Leviticus 19:18); in Christianity, “All things whatsoever ye would that men should do to you, do ye so to them” (Matthew 7:1); and in Islam “No-one of you is a believer until he desires for his brother that which he desires for himself”.

If we are to heed these teachings, to ensure that the voice of moderation can continue to be heard, and to oppose extremism, what do our understandings of God, implicit in our faiths, have to say that might help us? First of all, the Good Lord surely does not mean us to kill each other – that is in all our traditions.

Secondly, in a world of abstractions, materialism and loss of spiritual meaning, surely those of us who share a faith in something beyond merely ourselves, beyond the ego and the passions, beyond the worship of science for its own sake, who have faith in a harmonious universe that balances mind, body and spirit, the heart and the head, in an understanding of the divine order that is God's mysterious and loving gift to the created world – surely, surely we should be uniting together on the basis of our shared beliefs?

Surely the wisdom I have referred to earlier should warn us that far from fighting each other, or arguing about futile abstractions, we should be working together in the face of the immense environmental crisis threatening our entire planet? What, then, can we learn from Islam that will help us re-integrate ourselves with Nature? Can we not see the urgent need before it is too late to blend the intuitive genius of the East with the practical genius of the West?

Central to the teachings of all our faiths is an emphasis on respect for each other. This is much more than a political argument about the rights of minorities. Muslims, Christians and Jews are united in believing in the dignity and value of the individual. Each of us is unique and of unique value to God. When we know ourselves, our frailties and weaknesses, we can see the importance of understanding towards others – of seeing the other's point of view.

Respect for others, and for what is precious to others – in other words good manners, civility, and a willingness to listen – ensures respect towards our own values and ideals. The recent ghastly strife and anger over the Danish cartoons shows the danger that comes of our failure to listen and to respect what is precious and sacred to others. In my view, the true mark of a civilized society is the respect it pays to minorities and to strangers.

Generous, hospitable welcome to strangers and to those on their travels is justifiably a proud element of Arab culture. We in Britain have made great efforts to welcome people of other faiths, and to enable them to preserve their unique identities, while at the same time accommodating themselves to British culture. There are now more than a million and a half British Muslims. They enrich British society in countless ways, as, I am sure, do the Christian minorities in Muslim nations.

As people of faith, we know, too, that the human spirit is called to the horizon of eternity. We sense intuitively that we are too frequently focussed on the external world, which so often discounts what cannot be measured and weighed. But how can we measure or weigh Faith, Beauty, Loyalty, Joy, or indeed Love itself – all the things that make life worth living and help define the essence of our humanity? Do not these qualities represent an inner reality?

And, when we speak of an inner reality, we are in fact speaking of that dimension which sees beyond the material – in other words, we are speaking once more of the heart. We speak metaphorically of the heart as the source of compassion – the “charity” to which St. Paul refers in one translation of the Bible (King James version, I Corinthians 13) – which, for Christians, is the supreme virtue.

When we face problems of understanding between cultures and religions, is not what is missing just that perception: the perception of the heart which is kind, moderate and full of acceptance? This is the perception in which we can all share and which is brought to mind by the writings and example of the great mystics in our different traditions – people like Julian of Norwich, Rabbi Isaac Luria, and Imam Muhammad Idris al-Shafi.

Do not these great men and women, with their perennial wisdom, tell us of the need to balance our often aggressive and superficial behaviour with a more gentle, contemplative attitude – a turning from the head to that domain of the heart where the goodness in our common humanity is to be found? Let me be clear: this is not an argument about contemplative withdrawal, but rather a prescription for active engagement in our dealings with others.

After all, we share together a tradition of revelation that has informed the very essence of our faiths. Interestingly, science is beginning to discover the order and harmony inherent within Nature – something that was revealed to the ancients thousands of years ago. Surely this indicates a profound truth about the pattern of the inner life and its relationship with God's mysterious pattern for the manifested world?

I believe we have a shared duty to speak for the principles of our religious faiths. I believe we must protect the integrity of all our traditions – Muslim, Christian and Jewish – acknowledging and celebrating our rich diversity which, at the end of the day, is our only guarantee against the domination of a uniform, monocultural, global culture, whether religious or secular.

And I believe that, to defend the realm of the spirit against materialism, and the transcendent dignity of each one of us against extremism and self-idolatry, we must foster, encourage and act upon that which embodies the divine attributes of mercy and compassion. That calls for calmness and the exercise of restraint. And, if I may say so, it requires all those who are in positions of authority in our different faiths to preach clearly and consistently to others the eternal value of these Divine attributes.

Some three thousand years ago King Solomon, the son of David, said, “Where there is no vision, the people perish” (Proverbs 29:18). I can only say that I look forward to a world in which we share a vision that acknowledges our differences with respect and understanding; that recognises what others hold sacred – and to a world in which we see that we cannot, and must not, abuse our great traditions and their teachings as a weapon in the service of selfish, worldly power.

I have no illusions about the difficulty of this task. But I believe it is one which now, above all times, we must undertake, and undertake together. There is no other way to preserve the innermost values of our faiths which we hold most dear. We must work together to create a world in which the fruits of faith – understanding, tolerance and compassion – enrich and safeguard the world of our children, and our children's children. We must not let slip this opportunity and this challenge in an age which requires our determined, committed and heartfelt efforts to live in peace together.