As religious head of the Church of England and symbolic head of the worldwide Anglican Communion comprising almost 80 million worshippers, the Archbishop of Canterbury's position is the most political of religious roles. Dr Rowan Williams, described as Anglicanism's cleverest, most gifted and pre-eminent theologian, meets with Sarah Joseph in his study at Lambeth Palace.

His voice is gentle; one strains to hear him. It creates an atmosphere of silence, of contemplation, as you have to still yourself in order to absorb his words. There is no booming personality, no highs and lows of punchy rhetoric, no sound bites or, as he says, 'rent-a-quote', but rather a series of profound views expressed in serene tranquillity.

In this atmosphere, we discuss violence and the clash of civilisations. "I am very sceptical about fixing the identity of civilisations in an eternal form as if they are bound to clash with each other. Civilisations develop in dialogue and this has been quite a part of Muslim Christian history." He is more convinced by the clash between religion and the contemporary world, "Our modern western definition of humanity is clearly not working very well." A theme we come back to later.

I ask him if America has lost the moral high ground since September 11th, and his answer is simple: "Yes." There is no mitigation. He has obviously thought through what he feels the US should do now to recover, "A generous and intelligent programme of aid directed to the societies that have been ravaged; a check on the economic exploitation of defeated territories; a demilitarisation of their presence. All these things would help."

He describes violence as "a quick discharge of frustration. It serves you. It does not serve the situation. Whenever people turn to violence what they do is temporarily release themselves from some sort of problem but they help no one else." A long term critic of the war on Iraq, he feels that this perspective on violence also applies to Britain's presence there. "A lot of the pressure around the invasion of Iraq was 'We've got to do something! Then we'll feel better.' That's very dangerous."

In a country where faith and politics are essentially divided, in Alastair Campbell's infamous words, "we don't do God", the Archbishop does feel he has a role to play within the political arena. On the Iraq war he wants to "keep before government and others the great question of how you can actually contribute to a responsible civil society in a context where you've undermined most of the foundations on which that society can be built." And he plainly feels responsibility for the "beleaguered Christian communities in Iraq, who are now suffering because their neighbours have turned against them, identifying them with the West."

He also feels responsibility towards Palestinian Christians in the Holy Land. He refers to a trip he made last Christmas with other Christian leaders to "deliberately draw attention to our Christian brothers and sisters in Bethlehem." He condemns the wall which cuts in half that most special of places where the Christian narrative says Christ was born. "Whatever justification given for the existence of the wall, the human cost is colossal. We saw that for ourselves." He is adamant in calling it a wall and not a fence, "I haven't seen very many fences of that size and thickness." Indeed, Israel's "security fence" is made up of a triple layer of concrete and metal, equipped with electronic sensors and patrolled by army jeeps, ostensibly to keep out the terrorists, but in effect keeping ordinary civilians caged.

I ask the Archbishop about the relationship of modern Christians to the Holy Land and he paints a complex picture. "At one end of the spectrum you have Christian Zionism which is very interested in the Holy Land in ways which I find very strange, and not at all easy to accept. At the other end of the spectrum you have Christians for whom the Holy Land is some distant theme park." He does however feel that a "growing number of Christians have become aware of the reality of the situation on the ground" and journeys there have helped "expose their minds and hearts to the realities." He wants to see those numbers growing.

Christian Zionists support the return of Jews to Israel because they believe the second coming of Jesus will not occur until all Jews are in Israel. The Archbishop is scathing, accusing them of being connected to "the chosen nation myth of America, meaning that what happens in America is very much at the heart of God's purpose for humanity."

In today's world it is easy to see why people would believe such an idea; America seems so intrinsically involved in everything. The Archbishop recognises that: "We have only one global hegemonic power at the moment." But, he propounds, "It is not accumulating territory; it is trying to accumulate influence and control. That's not working." Far from seeing this positively, he describes it as "the worst of all worlds," saying, "it is one thing to take over a territory and then pour energy and resources into administering it and normalising it. Rightly or wrongly that's what the British Empire did – in India for example. It is another thing to go in on the assumption that a quick burst of violent action will somehow clear the decks and that you can move on and other people will put things back together –Iraq for example."

Beyond the tensions of international disputes, we discuss the more fundamental conflict between religion and modernity. "There is an essential clash somewhere. It is to do with the functional view of human beings. What are humans for? The Muslim, the Christian, the Hindu, the Sikh, would say that we are for the glory of God; so that God's light may be reflected and God's love diffused. It is never just about how we fit into the cogs of society, or about economic production. The more our education system is dominated by functionalism, skills, productivity, and the more our whole society is determined by that kind of mythology, the harder it is for the religious voice to be heard. There is a real abrasion between lots of the forms of modernity and religion."

I ask what we can do to restore balance, particularly in children. "They need more time: time to grow, time to play, time to discover themselves. They need space for the imagination. They don't need to be protected, supervised and muffled at every turn. Otherwise they end up very pale spiritually and physically." As a mother of three young children, I can testify to the truth of his words. I am often frustrated by the inability of the system to allow children to evolve their own individual identities at their own pace.

Indeed the increasing pace of life is something which obviously bothers the Archbishop and he jokes that he wants to put "a lot of activity into slowing people down," but his is a serious point. He calls upon individual believers to be faithful to their traditions and to make time for God. He commends the Muslim ritual of five daily prayers, which allows for such remembrance of God to be "built deeply into their daily rhythm." He also gives tips on slowing one's life down: "Exercise real discernment about what activities you take on; if you can't make all the difference find out the difference that you can make. The characteristic style of the believer in the political and social world is measured action that requires time to mature."

However, ultimately he believes that "there is a conflict at the essential level. There is something about western modernity which really does eat away at the soul. If the soul is, to give the most minimal definition, that dimension of us which is most fundamentally in conscious relation with the Creator, then those things which speed us up and harden us are going to get in the way of the soul. We don't know how to talk about it any longer but it is language that we still reach for. The worst message we can give off is compulsive anxiety, 'I've got to fix everything'."

Throughout our discussion the themes of fear and anxiety are played out in different ways. Increasing fanaticism and obsessions with "the uncontrollable other" are due to fear and anxiety which ultimately he believes is a lack of faith in God. "When belief is weak we are not willing to let things rest in God's hands because we are not sure that they are there. We can't trust God sufficiently to rest in what we are and who we are." For the Archbishop, "confidence is a key; the right kind of confidence; not arrogance, but real trust in God."

I put it to the Archbishop that some fears are grounded in reality and have very real consequences for individuals. We discuss the impact of legislation in Europe: the Swiss 'Kin Liability' that would see entire families of immigrants deported if one member is convicted of a crime; the Danish legislation that banned its citizens who are under 25 from marrying a foreign national, and other such repressive moves throughout Europe. Whilst calling for the good stories to be told, he believes society has to "ask some very basic questions about the myths of national identity and legal power that underlie this. We are dangerously close in lots of European settings, not so much here, to having a picture that the essential political unit is one which the State grants license to other bodies to exist, instead of the State working with and mediating between the communities which are actually there. I think this sort of legislative philosophy depends on the idea that the starting pointis always the neutral secular State and that the religious or ethnic other is an intruder into that space. And if you want to be taken seriously then you have got to leave your clothes at the door." He rejects this political philosophy and holds that the "Church has the responsibility and the capacity to ask some fundamental questions about political society and community."

Beyond his role as the Archbishop of Canterbury, Dr Williams obviously believes that there is a deep and real purpose for the Church in society. We discuss Jesus as an individual shared by both the Christian and Muslim tradition and I ask him if Jesus is a role model, "Not in celebrity terms, but someone whose style and rhythm and direction of life was one that we seek to realise in our lives." But was he a revolutionary? "Yes, so revolutionary that he puts all revolutions into question. The change is so different that it is not so much a change from one system to another, but a change from one world to another. A new creation where our relations to each other are no longer mutually suspicious or exclusive or competitive, but entirely shaped by giving and receiving – building one another up by a community of transformed persons, not just by a new legal system. That's revolutionary."

His views about ultimate transformation are more profound than mere social change. I ask him if Christians have become tame. He agrees, "We listen to the most extraordinary and outrageous things in the New Testament and we doze through them." He cites the example of the Samaritans, a people reviled at the time of Christ, but who we now associate with righteous deeds. "To get the full force of the parable of the Good Samaritan we have to use another word: the good asylum seeker, the good Muslim, the good teenager in a hoodie. You have got to get the sense of the unexpected, the despised. That's what the parable is about."

Despite the fact that "differences matter" in the understandings of Jesus in Christian and Muslim narratives, he feels that "mutual probing" can be beneficial for both sides. He advocates a "mutual covenant of religious peoples" to address a media world "very happy with the stereotypes of the other" and feels "Britain is potentially very fertile soil" for building a plural, mutually respectful society, particularly if we meet at the ordinary level of schools and neighbours. He feels that such meetings would help Muslims see that "not everything about the West is destructive, secular and undermining of virtue." And such engagement would help dispel the myth that Muslims must be "different in every way if they are different in any way."

The Archbishop is not afraid of differences. He does not advocate glossing over them, "disagreements do stand; it is part of the fabric of humanity that we learn by differences." He is not afraid of being critical of Muslims either. In Pakistan he was "surprised by how the extremely small Christian minority there is perceived as so deeply threatening by an overwhelming Muslim majority which ought to be more confident and generous about its identity." He also feels that the Muslim world should be ready to acknowledge that their "present political solutions aren't always very impressive," and that there is something to learn from asking questions of "classical liberal democracy that might fit with an Islamic world view."

At the same time he obviously feels that the West has the opportunity to learn a great deal from the religious heritage of others and that an engagement with the religious is something lacking in our society. He describes art as a substitute religion and says, "Forms of modern religiosity penetrate a little through the hard service of modern secularism, but there is something much greater and deeper – another level to get to entirely – where we understand the fundamental dignity of our lives in the face of God."

As I listen to the words of Dr Williams, I feel it tragic that global Anglicanism seems intent on tearing itself apart when it really needs to look beyond internal strife and engage with others on the great issues troubling the world today. There is much to absorb from his insight, and one wishes more Muslims could have greater access to him. One also bemoans the scarcity of persons of his calibre in the British Muslim landscape, but then he is quite extraordinary, even amongst Bishops!