ROME – Addressing inmates in a federal prison in Argentina, Pope Francis said on Thursday that serving time behind bars without any hope of eventually being reintegrated into society is not punishment but torture.

In a video message, Pope Francis congratulated the inmates of Argentina’s Ezeiza Federal Penitentiary who are attending university while in jail, and thanked all those involved in the project for helping those serving time for a “mistake they made” to reintegrate into society.

“Life, as you know, is a gift, but one that must be conquered every day,” Francis says in the video, released by the Vatican on Thursday. “Life was gifted to us, but we must conquer it on every step of the way.”

Francis told the inmates that even though “difficulties abound” in life, no matter who you are, the gift of life must be cared for and made to flourish. He also acknowledged that those who are in prison are there because they “made a mistake” and they have to pay for it.

“But let us not forget that for the punishment to be fruitful, it must have a horizon of hope,” he said. “Otherwise, it is enclosed within itself and is only an instrument of torture, it’s not fruitful.”

Punishment, he said, includes the hope of social reintegration, which comes through social empowerment and education.

Francis sent the video to the Ezeiza Federal Penitentiary, located some 20 miles from Buenos Aires’s famed Plaza de Mayo, where the then-Cardinal Jorge Mario Bergoglio used to live.

The Argentine pope is well acquainted with this particular prison, which he used to visit when he was still the Archbishop of Buenos Aires, and to which he still makes weekly phone calls, every Sunday, as he reveals in the message.

Though the message is clearly personal, with Francis addressing many of those involved in the program by name, the fact that he took the time to hand-write his words shows it was also important for him to get his message across to a wider audience.

The pope sent the video to mark the opening of a musical workshop for the inmates, carried out with the help of Buenos Aires’s public university (UBA), the second-largest university by enrollment in Latin America.

The music workshop is part of a larger program called UBA XXII Century, present in five Argentine jails. For over two decades, it has allowed prisoners to get degrees in social services, sociology, philosophy, management and law, among others.

“I’m aware of all your activities, and I am very happy with the existence of this space, a space of work, culture, progress … it’s a sign of humanity,” Francis said.

Since the beginning of his pontificate, Francis has been an outspoken supporter of social reintegration of criminals, choosing to celebrate three of his four Holy Thursday Masses in different Roman jails, picking up on a tradition he developed when he was archbishop of Buenos Aires.

Beyond the Maundy Thursday tradition, Pope Francis has made several appeals intended to shine a spotlight over the conditions prisoners live in, visiting jails on most of his foreign trips, including in the United Sates, where he visited a detention facility in Philadelphia.

During the Holy Year of Mercy, one of the final major events was a Mass celebrated in St. Peter’s Basilica with over 1,000 inmates from all over the world.

In an interview ahead of this year’s Holy Week, Pope Francis explained where his emphasis on reaching out to inmates comes from: “The Gospel passage on the universal judgment says: ‘I was a prisoner and you visited me,’” Francis told the Italian newspaper La Reppublica. “This is Jesus’ mandate for all of us, but especially the bishop who is father of everyone.”

Talking about prisoners, the pope said “Some say: ‘They are guilty,’” the pope said. “I respond with Jesus’ words: ‘Whoever is not guilty, throw the first stone.’ Let’s look inside ourselves and we will come to see our own guilt. And then the heart will become more human.”