At 78, Father Lusarreta has lived through the bad times and the good in the Catholic Church's relations with the Cuban government, from the days of state atheism to the eager preparations for the pope's upcoming visit.
Throughout the communist regime's gradual reconciliation with religion, the Spanish priest has always found the space to run his charity, La Milagrosa (The Miraculous), a symbol of the important social role the Church has assumed on the island.
Jesus Maria Lusarreta arrived in Havana in 1993, the year after Cuba amended its constitution to abolish more than three decades of state atheism.
The island was in the middle of its so-called "special period," the days of acute poverty that followed the collapse of the Soviet Union, its main benefactor.
It was a time when Fidel Castro's government was allowing the Church to take on a significant role in social welfare programs, long the exclusive territory of the ruling Communist Party.
Against that backdrop, Lusarreta moved to the island and started work at his new parish in a poor Havana neighborhood known as October 10.
He launched his charity in 1996 as a soup kitchen to provide meals for elderly residents with no family to support them and only meager pensions to survive on.
"We started with 12 people. By the end of the year, there were 60. But we didn't have enough food. So in '97 I got the idea to write a letter to Fidel Castro," said Lusarreta, a jovial figure with a piercing gaze.
The "maximum leader" replied that the priest had his support, and granted him a regular subsidy from the government, he said.
Since then, La Milagrosa has become a neighborhood institution that feeds more than 200 people three times a day, and Lusarreta has started a string of other social programs for the poor and downtrodden.
- Pope for today's Cuba -
It is the type of charity that embodies Pope Francis's vision of a "poor Church, for the poor," which the Argentine has made a central pillar of his papacy.
For Lusarreta, the first Latin American pontiff's emphasis on the Church's social role hews closely to Catholicism's new place in post-Cold War Cuba.
"Me, I love the pope, precisely because he has spoken out very clearly, simply and concretely," he told AFP.
"That's the Church I like."
Beside his soup kitchen, Lusarreta has opened a two-story "grandparents' house" where retired residents gather after morning mass to chat, read, watch TV and play dominos, a Cuban national pastime.