The Archbishop of Canterbury today urged people to pray for the leaders of America as they considered how to respond to the terror attacks.
He said those responsible for Tuesday's "barbaric acts" must be held to account, but he added: "We must be guided by higher goals than mere revenge."
Dr George Carey said: "We have gathered today, not only inside this great cathedral but outside as well, to share in America's grief and to mourn the loss of so many lives.
"Like millions of others, I watched in horror as the towers of the World Trade Centre disappeared under a cloud of dust and smoke.
"A modern icon of America had been reduced to rubble. A senseless evil had been perpetrated against America and the free world.
"In the aftermath of such shocking events, various emotions arise within us. We may feel despair at man's inhumanity to man.
"We may feel helpless that we can do so little for those who have suffered so much, among them many hundreds of British people - they and their families are very much in our thoughts and prayers at this time.
"We may feel anger against those who planned and carried out such evil, despicable deeds. We may want to see revenge. We may just feel numb.
"But my first word today - echoed I know my every faith leader present and by us all - is a simple message to the people of America through the American ambassador: a message of love and solidarity, a message also of hope.
"What you have gone through during the last few days is beyond our imagination. As we gather with Her Majesty the Queen, the Government and other political leaders, our hearts go out to you - you are all firmly in our prayers. We hope you know that we are with you in your hour of need.
"And next let me affirm that true faith is never overcome by disasters of this nature. There is something unconquerable about the faith we share.
"With St Paul, we trust that 'neither death, nor life, nor angels, nor principalities, nor powers ... Nor any other creature shall be able to separate us from the love of God in Jesus Christ Our Lord'.
"And even in the darkest hour, such faith in God gives birth to hope. So into the trauma of the people of America, let us declare the hopeful words of the prophet Isiah, first spoken at a time of disaster and despair in the life of his own people:
'They shall build up the ancient ruins.
'They shall raise up the ancient and former devastations, they shall repair the ruined cities ...'
"I am hopeful for the people of America - hopeful that as ruins are rebuilt, so also a shaken people will be restored.
"For as the twin towers of the World Trade Centre disappeared amid the smoke and carnage, across a short stretch of water, another, older American icon was not submerged.
"The September morning sun continued to shine on the Statue of Liberty, her torch raised like a beacon - a beacon of hope and to millions around the world, a symbol of all that is best about America.
"Liberty has always been at the heart of the American vision. That liberty must be defended. It is the awesome responsibility of the leaders of America to decide how to respond to this evil inflicted upon their people, this assault on their freedom and security.
"The leaders of America need our prayers. May God give them wisdom to use their great power in such ways that further evil aggression is indeed deterred, and the security and well-being of all is advanced in our interdependent world.
"For the flower of democracy to flourish, it must grow in the soil of justice. Yes, those responsible for such barbaric acts must be held to account. But we must be guided by higher goals than mere revenge.
"As we battle with evil, our goal must be a world where such violence is a thing of the past.
"The idea and ideal of liberty at the core of America's greatness - the liberty symbolised by that statue emerging unscathed from the pall of devastation - was founded on a noble community of values in which we are proud to share.
"Values like tolerance and compassion, justice and mercy. Values at the heart of the Christian faith and also of other great faiths.
"Let us keep them before us now - like a torch, like a beacon - even as we mourn and grieve.
"For if we are steadfast, we know that, by the grace of God, no darkness, no evil can ever extinguish that beacon of hope."Reuse content