Pope Francis is hoping to persuade a country enmeshed in a regional war that he has condemned to give Catholics more freedom when he becomes the first pontiff to set foot on the Arabian Peninsula.
Francis will spend less than 48 hours in the United Arab Emirates, which is fighting alongside Saudi Arabia in the Yemen war, and is due to make only two public addresses during the trip that starts on Sunday night.
Although short, the visit to the peninsula, home to 2 million expatriate Catholics as well as the holiest sites of Islam in Saudi Arabia, is a landmark one. The freedom to practice Christianity, or any religion other than Islam, varies across Gulf countries.
The papal Mass in Abu Dhabi's Zayed Sports City on Tuesday is expected to draw 120,000 people.
"I am happy for this occasion the Lord has given me to write, on your dear land, a new page in the history of relations between religions," Francis said in a video message on Thursday.
It started in Arabic with the words Al Salamu Alaikum (Peace be with you).
"Faith in God unites and does not divide, it draws us closer despite differences, it distances us from hostilities and aversion."
Priests, worshippers and diplomats in the UAE say it is among the most tolerant countries in the Gulf region toward other religions.
In the UAE and Kuwait, Christians may worship in churches or church compounds, and in other places with special licences. In Saudi Arabia, churches are banned.
Francis praised the UAE as "a land that is trying to be a model of coexistence, of human brotherhood, and a meeting place among diverse civilizations and cultures."
He has already visited half a dozen predominantly Muslim nations and has used those trips to call for inter-religious dialogue and to condemn the notion of violence in the name of God. In March, he will go to Morocco.
The war in Yemen, which the pope has condemned several times, could cast a shadow on the trip.
Last June, he said he was following the "dramatic fate of the people of Yemen, already exhausted by years of conflict," and appealed to the international community to seek negotiations "to avoid a worsening of the already tragic humanitarian situation."
The UAE has played a leading role in the Saudi-led coalition waging a nearly four-year war against the Iran-aligned Houthi movement in Yemen.
Rights groups have accused UAE-backed forces of torturing detainees in areas under their control in Yemen, charges the UAE has denied. The UAE says it has never run prisons or secret detention centers in Yemen and that prisons there are under the authority of the Yemeni government. Its Yemeni allies have denied allegations of torturing prisoners.
"I don't think the pope will be silent about what is happening in the region," Bishop Paul Hinder, the Abu Dhabi-based Apostolic Vicar for Southern Arabia, said in an interview when asked if the pope would speak about the war.
But he said he did not know if the pope would mention it in public or in private meetings with UAE leaders.
The pope will meet privately with Sheikh Mohammed bin Zayed al-Nahyan, Crown Prince of Abu Dhabi, who invited him.
"There may very well be some people who will criticize him for going [because of the war in Yemen], but I expect that he will raise this issue as he has previously," a Western diplomat said.
Francis will also visit Abu Dhabi's Sheikh Zayed Grand Mosque, the largest in the country, and hold a private meeting there with the Muslim Council of Elders.
Vatican officials call Catholic communities such as those in the UAE "passport churches" because the priests, like the mostly Filipino and Indian Catholics they minister to, are foreign and need permission to live and work there.
This is different from other mostly Muslim countries like Syria and Iraq, where there have been local Catholic communities and priests for centuries.
Vatican officials say they hope one of the immediate effects of the visit will be permission to build more church compounds in the UAE to minister to the Catholic community.
"We are really stretched. We need more churches. We need more priests," one official said.