"These were the people who understood that Latin America had a huge contribution to make to the world of theology, considering that close to half of Catholics were living on the continent," he said.
This approach emphasized the preferential option for the poor, and that popular piety and devotion would play a major role in unifying Latin American, and in preserving and transmitting the faith across the continent.
"That's where the Pope's preference for the importance of Marian shrines, and processions and events of massive faith comes from," Bermudez said, explaining that because of the way in which people gathered to celebrate their faith in this "popular" way, the approach later became known as the "teologia del pueblo."
"What is known today as the 'teologia del pueblo' didn't exist at that time," Bermudez said, explaining that the "theology of the people" was a later evolution of Latin American theology,
Bermudez stressed that these ideas were different from liberation theology, which sprung up in Latin America in the 1970s, and often emphasized a Marxist interpretation of the Gospel, viewing faith through the lens of class struggle, rather than giving primacy to spiritual freedom.
He explained that liberation theology largely rejected popular piety, believing it to be "some kind of backwards approach to religion that would keep people away from social change and structural change."
Liberation theology was not relevant in Argentina at the time of Bergoglio's formation, Bermudez said.
When Bergoglio was being formed, Bermudez said, "there was a lot of hope in a Latin American future in which Latin America would play a huge role in the world," he said, but noted that in the years since, "crisis and corruption and political squabbles pretty much put an end to any hope that Latin America would raise up as one single nation."
However, the influence of the "teologia latinoamericana" can clearly be seen in Francis' words, actions and personal style, above all in his emphasis on community and solidarity, which Bermudez said stems from the belief that popular devotion "was a richness that allowed the people of Latin America to preserve and persevere in their faith."
Another manifestation of this formation is the hope Francis has for Latin America's role Church, since it covers such large swaths of territory, from the Rio Grande to the Tierra del Fuego.
"You can hardly find any other place in the planet when you can go through such a large territory and be celebrating the same faith and speaking the same language," Bermudez said, adding that while he's not sure if Pope Francis has a specific belief in the "great future" of Latin America, he still has a tremendous hope for the continent.
Likewise, Ivereigh said this influence can be seen even from Bergoglio's time as rector of the San Miguel seminary in Buenos Aires, where he kept a strict spiritual and academic regime for the Jesuit novices, while also encouraging them to pray the rosary together and sending them out to minister in parishes on the weekends.
"His vision of the Church, I think, derives from his reading of the Spanish missionary experience in the colonial era of Latin America. He makes frequent references, particularly in Latin America, to that era," Ivereigh said.
Bergoglio wanted the seminarians to "get out of their heads and have contact with the people; so study was important, but on weekends they were out there with the people ministering in the parishes," which was unusual for Jesuits at the time, who typically placed a heavy emphasis on academics.
After the Second Vatican Council, Bergoglio was "very skeptical of progressive attempts to depart from core Catholic traditions," such as, in his view, downgrading the importance of popular piety, Ivereigh said.
"He was very strong on maintaining that," Ivereigh said, explaining that Bergoglio's approach was consistently about "going back to the original charism of the 16th century Jesuits," which placed a strong emphasis on missionary outreach.
"He certainly didn't want to go back to the former time before the Council, but he didn't want a modernization that would dilute the Catholic tradition, and he wanted a deeper reform that returned the Jesuits to their deeper traditions."
How his formation shapes his papacy
Both biographers noted that, while the Pope has limited formal theological training, his formation and intellect can be seen in his daily words and actions.
For Ivereigh, Francis' entire 5-year pontificate has so far been "one big lesson in what they call in Latin and Italian 'pastoralita' – it's one big lesson in how to be pastoral...putting people first, spending time with them, showing that everybody is valuable, showing that God cares about everybody."
This is seen in Francis' homilies and travels, but also in his interaction with media and his general approachability, Ivereigh said, explaining that in his view, the Pope is constantly trying to remove "unnecessary blockages" getting in the way of reaching the people.
"Some of those blockages are the result of social and cultural change, which lead people for example to be suspicious of institutions or to see institutions as distant. But some of those blockages are also part of the Church's culture," he said. "So the proclamation has to be simpler, humbler and more kerygmatic. That's been his big message of these last five years."
In his view, Bermudez said the influence of Latin American theology, in particular, can be seen clearly in the Pope's continuous encouragement for priests to take on the "smell of the sheep," as well as his ideas about how the priesthood and episcopate should be based on the "conviction that the faith of the people is very powerful."
Since the beginning, Francis has preached the importance of popular devotions, the need for greater hope and solidarity, the importance of truth, a sense of good and evil and an emphasis on divine intervention, Bermudez said.
"All that has been influenced by this experience of the common people, your day-by-day Catholic who lives from Church feast to Church feast and experiences their faith [in this way]," he said, adding that this approach has "completely impregnated his preaching and his vision of how to live our faith."