The head of Sunni Islam's highest seat of learning has urged the Middle East's Muslims to "embrace" local Christians.
Sheikh Ahmed al-Tayeb, the grand imam of al-Azhar in Egypt, told an interfaith meeting in Abu Dhabi attended by Pope Francis that Christians were "our companions".
He also called on Muslims in the West to integrate into their communities while maintaining their identities.
In his speech, Pope Francis called for a halt to wars in the Middle East.
The head of the Roman Catholic Church, who is on his first official visit to the Arabian peninsula, said the "fateful consequences" of violence could be seen in Yemen, Syria, Iraq and Libya.
The United Arab Emirates is part of a Saudi-led coalition whose intervention in the conflict in Yemen has helped trigger the world's worst humanitarian crisis.
Sheikh Ahmed and Pope Francis addressed a gathering of religious representatives at the Abu Dhabi Founder's Memorial on Monday night after signing a "Document on Human Fraternity for World Peace and Living Together".
The document calls on leaders of the world to work together to "spread the culture of tolerance" and to "intervene at the earliest opportunity to stop the shedding of innocent blood and bring an end to wars, conflicts, environmental decay and the moral and cultural decline the world is presently experiencing".
It also includes a strong condemnation of those using God's name to justify violence. "God, the Almighty, has no need to be defended by anyone and does not want His name to be used to terrorise people," it states.
Christians - and members of other religious minorities - have been attacked repeatedly by Islamist extremists in countries across the Middle East in recent years. They have also faced restrictions on their ability to practice their religion, as well as legal and social discrimination.
In his speech, Sheikh Ahmed first addressed his fellow Muslims in the region.
"My message to you is: 'Embrace your Christian brothers and sisters. They are companions in the state. They are close to us. There are special bonds between us,'" he said.
He then turned to Middle Eastern Christians and said: "I'd rather you didn't use the term 'minority'.
"You're not a minority. You are citizens in every sense. Let's put aside that term. You are citizens with full rights. Our bond represents the rock against which all plots that try to divide us will break."
The imam also called on Muslims in the West to integrate themselves into their communities while maintaining their identities and respecting local laws.
"If you have any problems regarding your religion in the countries you find yourselves [in], you need to speak to your religious leaders and resolve them that way."
On Tuesday morning, Pope Francis will celebrate an outdoor Mass for some 135,000 people at the Zayed Sports City stadium in Abu Dhabi.