"A prophet is someone who comforts the afflicted and afflicts the comfortable. He speaks truth to power." It was US Jesuit Tom Reese who used those highly appropriate words when previewing the 10-day trip to Cuba and the US on which Pope Francis sets out this morning. Arguably, this 10th foreign trip of the Francis pontificate is the most important thus far – certainly in geopolitical terms.
Essentially, the pope is travelling to the US to attend the Catholic World Meeting of Families Congress in Philadelphia next weekend. Yet, while religious commentators will insist that a papal visit by Francis is essentially about sending out the gospel message of God's love and compassion, secular observers will wonder what message Francis will bring with him.
In this, his first visit to the US, will the pope – whose interests so clearly lie with the poor, the hungry and the dispossessed of the global south – chide America (and the West) for not doing enough?
In the heartland of capitalism, will he remind Americans that "an unfettered pursuit of money rules. This is the dung of the devil" – words he used in Bolivia on his last foreign trip in July?
In keenly anticipated addresses to the US Congress on Thursday and to the UN General Assembly in New York on Friday, will he remind listeners that “greed for money presides over the entire socioeconomic system, it ruins society, it condemns and enslaves men and women, it destroys human fraternity”?
In his first encyclical, Laudato Si, released this year, he argues that time is running out to save the planet from potentially irreversible damage to the ecosystem. When he sits down in the Oval Office with President Barack Obama on Wednesday, will he ask him what the US intends to bring to December's Paris climate summit?
There is no secret about the politics of Pope Francis, the pope who within two days of his election told the world that he would dearly love to have “a church of the poor and for the poor”. However, when – again in Bolivia – he suggested that “corporations, loan agencies, certain ‘free trade’ treaties” were often nothing more that a “new colonialism” that had come under “the influence of mammon”, alarm bells sounded in the US.
So then, is America about to receive an almighty dressing-down from the pontiff who sometimes sounds like the true leader of the European left? The answer is obviously No. Francis is much too astute to use the same language in Washington as in La Paz.
However, it is hard to believe that when he addresses Congress, he will not in some way call into question fundamental American beliefs in libertarian capitalism, globalisation and the consumer-based economy. In an age of a worldwide migration crisis, dramatically illustrated by events in Europe, he may even urge America to welcome the (undocumented) immigrant.
When he addresses the UN, you can take it for granted that he will call for peace and reconciliation worldwide and that he will denounce the persecution of Christians in the Middle East and Africa. At the UN, though, he may also express his environmental concerns, as articulated in Laudato Si.
Perhaps fittingly, this trip begins this morning in Cuba, a country which underlines easily the biggest diplomatic success of this pontificate, since both Cuban leader Raul Castro and Obama have paid tribute to his input into the Cuba-US detente of the last year.
Vatican spokesman Fr Federico Lombardi this week confirmed that during his stay in Cuba, Francis will meet also Fidel Castro, the historic father of the Cuban revolution.
In the build-up to this visit, there has been much speculation as to what language the pope will use. In Cuba, obviously, he will be at home in his native Spanish – but in the US? Presenting what he called a "long and complex" visit, Lombardi conceded that only four of the 18 speeches the pope is due to deliver in the US will be in English (at the White House, Congress and the UN).
Despite the tough message and lingusitic difficulties, hopes are high for this tour. Francis’s common touch and his ability to mix with people –he will be using an open-topped popemobile – ought to overcome reservations about his message.