There is much speculation about President Donald J. Trump’s first international sojourn as president, a nine-day trip to the Middle East and Europe. On Wednesday, Trump will have his first face-to-face with Pope Francis.

That pairing is even more incongruous than last month’s tete-a-tete between the Pope and former Fox TV star Bill O’Reilly.

On April 18, O’Reilly, on a family vacation, approached the pontiff in the VIP line at the Vatican, and they shook hands. That encounter came just hours before 21st Century Fox fired O’Reilly in the wake of a slew of sexual harassment allegations.

OPINION

That leaves this lifelong Roman Catholic to wonder. What will the Pope say to Trump? Can he offer hope, perhaps a biblical passage or a sprig of wisdom that might set Trump straight?

Wednesday’s reportedly private meeting will be between a man who possesses the world’s highest moral authority and a man short on authority of all kinds, moral and otherwise.

Trump seems most comfortable in his Oval Office sanctum, regally receiving world leaders who come to humbly bow and scrape for a share of America’s resources and might.

The Pope doesn’t need anything from Trump. He oversees the world’s 1.2 billion Roman Catholics, a constituency that dwarfs Trump’s. Polls show Francis is far more popular.

Yet, they have much to discuss. Francis has devoted his career to advocating for the poor, immigrants and refugees, people of color, war victims and others who personify the biblical credo of “the least among us.”

Trump spent his career getting rich, then running a slash-and-burn presidential campaign that labeled Mexican immigrants “bad hombres,” “rapists” and “criminals.” Trump says African Americans are “living in hell.” Trump assumes all Muslims are terrorists.

Not even the Pope was spared.

During the campaign, Francis told the media, “A person who only thinks about building walls — wherever they may be — and not building bridges, is not Christian,” apparently referring to Trump’s promised, xenophobic wall on the U.S. Mexico border.

“No leader, especially a religious leader, should have the right to question another man’s religion or faith,” Trump shot back at a South Carolina rally. “If and when the Vatican is attacked by ISIS, which as everyone knows is ISIS’ ultimate trophy, I can promise you that the pope would have only wished and prayed that Donald Trump would have been president.”

There are plenty of potential flashpoints for this conversation, from their differences on the treatment of immigrants and refugees to religious tolerance to capital punishment.

Fireworks? That seems unlikely, since, like all such diplomatic meetings, it will be heavily prepped and scripted.

Francis has offered a preview, recently telling reporters he would “look for common ground” at the meeting, according to NBC News.

“First of all, I never judge someone before I listen to the person. I can’t do that,” Francis said during a news conference on the papal plane. “We will talk and things will come up … I will tell him what I think, he will tell me what he thinks, but I never wanted to judge someone before I listen to the person first.”

Talk and listen, before you judge.

If Trump simply took that holy advice to heart, he could make exponential strides as a president — and as a person.

If only. Well, we can always pray.