ROME – When a new pope is elected, the first decision he’s asked to make is whether he accepts the job, and the second is the name by which he wishes to be called. The first answer is generally pro forma but the second can be monumental, sketching an outline of an entire papacy in one word.

Such was certainly the case in March 2013, when Cardinal Jorge Mario Bergoglio of Argentina indicated he wanted to be called “Francis.”

By taking that name, the new pope rolled the dice. Immediately, it allowed him to bask in the universal admiration that still surrounds the 12^th and 13^th century saint who loved the poor and preached to the birds. Yet it also meant he was placing massive expectations on his shoulders, because somehow the spirit of the saint is supposed to shine through the muck of governing the global Church and playing geopolitical chess – both arenas, frankly, where personal sanctity has proven over the centuries to be as much a liability as an asset.

Today, the pope travels to Assisi, the birthplace of Francis, to continue his effort to deliver on those expectations.

It’s the pontiff’s first trip outside of Rome since the coronavirus pandemic exploded, and his stops will be closed to the public due to limit crowd size and exposure risks. He’ll say Mass in the tomb where St. Francis is buried, celebrating in front of just a handful of Franciscan friars, and will only be in town for about an hour and a half.

The central reason for the brief outing is to sign a new encyclical letter, considered the most authoritative and developed form of papal teaching, which is titled Fratelli Tutti in a citation from one of St. Francis’s admonitions to his early Franciscan brothers. The title has generated a mini-kerfuffle among critics who object to the sexist language they perceive (“All Brothers”), though the Vatican has stressed the pope intends to include everyone.

This is the first time a papal encyclical has been signed outside of Rome, and Francis will do so in the same crypt where he says Mass. Although the text won’t be released until tomorrow, even before it comes out there are three reasons why it looms as potentially the most important document of this papacy.

First, it’s Francis’s first major document since the coronavirus crisis erupted. He’s certainly addressed the implications of the pandemic in a variety of other ways, including his evocative March 27 Urbi et Orbi blessing under the rain in an empty St. Peter’s Square, but this is his chance to present his thinking in a comprehensive, orderly, and fully formed way.

At a time when the world is still reeling from the virus – including from the news yesterday that even the President and First Lady of the United States have been infected – it’s desperate for leadership, and this is the pontiff’s opportunity to deliver it.

Second, although it’s a hackneyed cliché to say that the world stands at a crossroads, the world nevertheless stands at a crossroads vis-à-vis the vision Pope Francis has been trying to lay out for the last eight years.

A pope who’s a champion of European unity has watched Poland and Hungary spin progressively out of the EU orbit, while Great Britain formally walked away (and is now basically being sued for breach of contract). A pope who preaches welcome and compassion for immigrants has seen the US elect a president who ran on getting tough, and his own backyard in Italy was governed for a time by a deputy prime minister whose stock in trade was refusing to allow desperate migrants to disembark their rescue boats.

A pope who preaches non-violence has seen the Philippines, arguably the most vibrantly Catholic country in the world, embrace a leader who’s unleashed a torrent of extra-judicial killings; and he’s seen Brazil, a cornerstone nation in his own Latin America and the largest Catholic nation on earth, elect a head of state for whom Laudato si’, the pope’s environmental encyclical, is a sort of Magna Carta in reverse, outlining what not to do.

If Pope Francis is to have something like the impact on his era that St. John Paul II had on his, playing a role in the collapse of European communism, now’s the time – and Fratelli Tutti may be the best shot he’s likely to get at laying the intellectual, spiritual and political groundwork.

Third, Pope Francis recently sent shock waves through the Vatican by firing Italian Cardinal Angelo Becciu, the former “substitute” in the Secretariat of State and a man long seen as the embodiment of the place’s old guard.

The move fired hopes that perhaps the long-delayed reform of the Vatican under Francis has gained a new lease on life, but it also means that pressure on Francis to oversee that reform will grow, with the risk of becoming swamped by internal Vatican politics and losing focus on the papacy’s bigger agenda.

Fratelli Tutti is thus a chance for Francis to stand back from the minutiae, however critical it may be, and offer a reminder of the ends all those details are meant to serve.

If it works, the encyclical could provide additional momentum for reform, as Vatican personnel feel greater motivation to ensure they don’t step on the pope’s message. If it doesn’t, the lure of business as usual may be harder to resist.

Francis thus has a fair bit riding on how Fratelli Tutti plays out. To most Catholics, though, if there’s anyone you’d want on your side in such a high-stakes situation, the Poverello, or “Poor Man” of Assisi, St. Francis, seems an awfully good choice.

Follow John Allen on Twitter at @JohnLAllenJr.