Donald Trump's first overseas trip as president begins Friday with a pilgrimage of sorts. With stops in Saudi Arabia, Israel and the Vatican, Trump will be visiting the centers of Islam, Judaism and Christianity, the three major monotheistic religions.

But he's wading into deep waters with potential for missteps and disagreement. He'll meet with Muslim leaders despite declaring that "Islam hates us" during the campaign; he'll meet with Pope Francis, who advocates for countries to be welcoming to refugees.

"His message is going to be about unity," said U.N. Ambassador Nikki Haley.

Religious differences have produced conflict around the world and especially in the Middle East. Some argue that religion can be part of the solution, if leaders like Trump make stronger faith-based appeals.

"The way we've engaged the world has been strictly in material terms," said Robert Nicholson, founder of the Philos Project, which promotes greater religious engagement in the Middle East. "We think people do things only because of economics or because of some sort of political grievance, but in actuality religion drives huge numbers of people on this planet."

One cited reason for the failure of the 1993 Oslo Accords to settle the Israeli-Palestinian conflict was that it neglected the importance of religion. A few years later, Christian, Jewish and Muslim leaders mounted a peace effort on their own and agreed on a plan. It, too, failed, in part because political leaders failed to lend support to the religious leaders.

"These are huge achievements, but politicians don't seem to want to run with them," said Jonathan Sacks, who supported a faith-based peace approach as the chief rabbi of the United Kingdom. "It's never been connected to a political process. It's been a stand-alone."

Sacks' book Not in God's Name: Confronting Religious Violence outlined his case that the Abrahamic scriptures support compassion and tolerance rather than hatred and cruelty. He believes that President Trump, by meeting first with Muslim, Jewish and Christian leaders, has an opportunity to make progress where others have failed.

"The president of the United States, through his personal standing, might be able to say, 'Let's make religion part of the peace process,' " Sacks said, "because it's the only thing that's been left out of it until now."

The obstacles in Trump's way are nevertheless daunting. In Saudi Arabia and Israel, Trump will primarily be meeting with political, not religious, leaders.

"Just because you stand in a sacred place doesn't mean you hear sacred truths," said Serene Jones, president of the Union Theological Seminary in New York. "He is obviously picking and choosing [from whom] he is going to hear about these religious traditions. Clearly this is more of a political trip than one of seeking deep religious understanding."

Another potential problem is that the recent controversies surrounding Trump have so distracted him that he has not been able to prepare adequately for the trip.

"You're wading into deep waters here," said Nicholson. "There are definitely ways Trump can make missteps, either in relating with people from these communities in his private conversations or making public mistakes in terms of what he says."

Pope Francis is an outspoken advocate of welcoming immigrants and refugees. Given Trump's contrary views, disagreement in those areas could get in the way of a friendly chat in Rome.

In Israel, Trump faces a potential controversy with the question of whether he allows Prime Minister Benjamin Netanyahu to accompany him on a visit to the Western Wall in Old Jerusalem, claimed by both the Israeli and Palestinian sides.

Trump's biggest challenge is likely to come in Saudi Arabia, where he is scheduled to give a speech urging Muslim leaders to promote "a peaceful vision of Islam." Much may depend on how that speech is received, especially given his suggestion during the presidential campaign that "Islam hates us."

"He needs to show that he respects Islam [and] that Muslims have dignity," said Nicholson. "For a long time, much of the conversation in the U.S. has been that anything Muslim is bad. I think one of the most important things for him to do is to show that he understands that Muslims have a long and ancient and distinguished past, and that he respects it. I think one of the driving factors in the Islamic world is a feeling that they are not respected."

The challenges notwithstanding, Nicholson and others are willing to give Trump the benefit of the doubt on this trip.

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