Worshipers descend the stone stairs, worn smooth by millions of pilgrims over the centuries, down into the Grotto -- the spot Christians believe Jesus was born.

Incense fills the small stone room, which is noticeably warmed by the multitude of candles.

The Armenian Church Service inside the Grotto at the Church of the Nativity.

An Armenian Apostolic priest begins to perform sacred rituals as ancient prayers reverberate in harmony.

Upstairs in a different room, dozens of Greek Orthodox worshipers receive the holy sacrament. And in the next room over, a Catholic congregation sings hymns of peace.

All three denominations share the birthplace of Jesus. After the final prayer, local Christians depart to greet each other as they have for centuries. They are proud to be descendants of the first Christians. The diverse community has stuck it out through war, famine, and disease.

Latin Church Sunday prayer taking place inside the Church of the Nativity.

The question now, say Christian leaders, is whether their Palestinian community can survive Israel's decades-long occupation. Their fear is that the current exodus of Christians from the region could leave the land without a living church.

"Our biggest challenge is to keep them here," says Father Rami Askarian. "You need to build a government, a country, an identity for the people. We pray for that to have peace in this country."

Preparations are made for the Armenian Church Sunday service inside the Grotto at the Church of the Nativity.

Father Askarian fears his flock could be reduced to tourists and pilgrims in a couple of generations. And many church leaders say recent American foreign policy is only making things worse.

When US President Donald Trump officially recognized Jerusalem as the capital of Israel in a short speech at the White House last month, the presence of his Vice President Mike Pence, standing just behind his right shoulder, was much remarked upon.

That's because Pence is an evangelical Christian, a member of a community which has long pushed hard for the United States to make this declaration.

But for leaders of the Christian church in the city itself, the announcement was met with dismay.

'Increase hatred'

In December, amid reports Trump was planning to change Jerusalem's status, thirteen church leaders from 13 denominations signed an open letter warning of "irreparable harm" to the Holy City if the US implemented the change.

"Mr. President, we have been following, with concern, the reports about the possibility of changing how the United States understands and deals with the status of Jerusalem," read the statement they issued.

"We are certain that such steps will yield increased hatred, conflict, violence and suffering in Jerusalem and the Holy Land, moving us farther from the goal of unity and deeper toward destructive division. We ask from you Mr. President to help us all walk towards more love and a definitive peace, which cannot be reached without Jerusalem being for all."

Pence (L) and Netanyahu attending a welcome ceremony at the Israeli Prime Minister's office on Monday.

Before Trump's declaration, Pence was already planning a trip to the Middle East, to take place just before Christmas. Part of his agenda, he said, would be to help embattled local Christians, and focus on relief efforts for persecuted religious minorities.

But after Trump made his Jerusalem announcement, local church leaders changed their minds, and canceled their meetings with him.

A vote on tax reform in the US Congress moved Pence's office to announce that his trip would be delayed until January.

'Our fear is from America'

There is no denying that Christians around the Middle East face the risk of persecution. The terror group, ISIS, has killed many Christians, as well as Muslims, in Iraq, Syria, Egypt, and Libya. In many Middle East countries, Christians are not granted equal rights to Muslims.

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So, it is arresting to hear one of Jerusalem's highest-ranking Christian figures declare that the most pressing threat facing Christians in the Middle East is not from a terror group, but rather the White House.

The former Latin Patriarch of Jerusalem, 84-year old Michel Sabbah, says it was the destabilization of the region, resulting from the war in Iraq in 2003, that led to the increase in persecution of Christians from groups like ISIS.

"Our fear is not from our people, from Muslims. Our fear is from America," Sabbah tells CNN. "If [Trump] wants to defend Christians in the Middle East, he has to start [by] changing American policy in the Middle East: to [begin] a new vision of politics, built on life and ... not more death or destruction."

Driving away Christians from the Holy Land, say local clergy, is the perceived preferential treatment the US shows toward Israel, and the occupation of Palestinian lands, which means restrictions on the lives, movements, and opportunities of Palestinian Christians, as well as Muslims.

Israel, which blames Palestinian leaders for the failure of the peace process and says security considerations necessitate its ongoing military presence in the West Bank, says its record on Christianity is exemplary.

'We want to raise our kids'

Israel's Prime Minister Benjamin Netanyahu made his case recently in a Christmas message, arguing that Israel's Christians enjoy equal opportunities.

"I'm proud that Israel is a country [where] not only do Christians survive but they thrive because we believe in this friendship among people and we protect the rights of everyone to worship in the holy shrines [of their various religions]," Netanyahu said in the video message.

Morin Butto, a Catholic from Bethlehem, sees things differently, and worries that young people are increasingly looking abroad for a better life.

"Sometimes we feel like we can't do [anything]. We just keep hanging onto our land," she says. "We want to raise our kids here, [but] most of our relatives have left the country [because of] this political situation."

Sabbah has a piece of advice to the visiting Vice President on how he can help the Holy Land's Christians.

"American policy must change in the Middle East," says Sabbah. "If truly the American administration is Christian, go back to the commandment of love. You love Israel. That's very good. But you [should also] love the Palestinians if you're Christian. Jesus said, love everyone."