Prince Charles has called for greater respect between religions, saying his "heart is heavy from... never-ending death and destruction" in the world.
The prince said the row over cartoons of the Prophet Muhammad showed "the danger... of our failure to listen and to respect" others' views.
He was giving a speech at Al-Azhar University in Cairo on a tour of Egypt with the Duchess of Cornwall.
Charles was awarded an honorary degree by the university.
One of the few non-Muslims to have been invited to speak at the university, the prince told 800 Islamic scholars that religious leaders needed to encourage understanding.
"We must foster, encourage and act upon that which embodies the divine attributes of mercy and compassion," he said.
"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 values of these divine attributes.
"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."
He added: "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."
The prince said fears about growing misunderstanding between the West and Islam that he had more than a decade ago - expressed in a 1993 speech at the Oxford Centre for Islamic Studies - appeared to have come true.
"For so many, those years have been profoundly bleak. My heart is heavy from witnessing the never-ending death and destruction."
He added: "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."
An interview with the prince had earlier been broadcast on Nile TV, in which Charles spoke about similarities between Christianity, Islam and Judaism.
"People who are reasonable and responsible and feel things in the heart need to work even harder and speak up louder about the vital importance of understanding that the three great Abrahamic faiths share an awful lot more in common than perhaps people realise," he said.
The 15-minute television broadcast was pre-recorded at Clarence House before Charles and Camilla left for the official two-week visit to Egypt, Saudi Arabia and India.
The prince said he had been given an insight into the effects of terrorism as a young man when he suffered the loss of the great-uncle he also regarded as his mentor in 1979.
Lord Mountbatten was on a fishing trip in the Irish Republic when his boat was blown up by the IRA.
Charles said he has "some understanding... of what people go through with these horrors".
He added: "It seems to me that we have to work even harder."