Around135,000 worshippers gathered in Zayed Sports City stadium in Abu Dhabi, the capital of the United Arab Emirates, to see the pope.
Tens of thousands of Catholics and several thousand Muslims attended an unprecedented public celebration of Mass on Tuesday by Pope Francis, the first pontiff in history to visit the Arabian peninsula.
Around 135,000 worshippers gathered in Zayed Sports City stadium in Abu Dhabi, the capital of the United Arab Emirates, to see the pope, who is in the Gulf Arab country to promote inter-faith dialogue.
"For me as a Christian, this is one of the most important days of my life," said Thomas Tijo, a 44-year-old from India's southern state of Kerala, who lives in the UAE and travelled by bus in the early hours to get to the stadium.
"We are a long way from home and this is like a comforting blanket. I will listen very carefully to what the pope says," he said, holding his three-year-old son, Marcus, and remembering seeing Pope John Paul in Kerala in 1986 as a boy.
The UAE is home to about half of the 2 million expatriate Catholics living on the Arabian peninsula, home to the birthplace of Islam in neighbouring Saudi Arabia.
Thousands of people cheering and waving Vatican flags lined the entrance to the stadium, with the Sheikh Zayed Grand Mosque in the distance.
Catholics from about 100 nations were expected to attend the Mass, along with about 4,000 Muslims, including government officials, organisers said.
The pope, who arrived on Sunday at the invitation of Abu Dhabi's crown prince, has used the visit to condemn regional wars, including that in Yemen, and to call for greater cooperation between Christians and Muslims.
He entered the stadium in a white open top jeep to roars from the crowd. People wearing white baseball caps emblazoned with the visit logo packed the stadium stands and snapped pictures on their smartphones.
The Mass was "a moment of divinity that will stay with me forever," said Josephine Periera, a 68-year-old retired teacher who had travelled from the Indian Ocean nation of Sri Lanka to attend.
A central part of the Christian faith, the Mass commemorates Jesus' Last Supper with his apostles on the night before he died. Catholics believe the communion host and wine become the body and blood of Christ when consecrated by a priest during the Mass.
Catholics believe the pope is the vicar of Christ on earth, so that participating in a papal Mass is particularly special.
Priests and diplomats describe the UAE as one of the least restrictive environments in the Gulf for Christian worship, which is allowed in church compounds with special licenses.
But, like other Gulf states, it outlaws unsanctioned religious gatherings and non-Muslims must not proselytise.
Newspapers in Saudi Arabia, where churches are banned, ran pictures of Francis' meetings with the grand imam of Egypt's Al-Azhar mosque in Abu Dhabi on Monday and Abu Dhabi's crown prince and Dubai's ruler.