This morning the "Ode to Joy" rang out from a teenaged orchestra as Pope Francis entered a room packed with 400 Italian school children from disadvantaged homes. They waved and cheered as the Pope spoke to them in simple terms about the importance of light and love in a dark world.

Today's meeting was the second of its kind, a collaboration between the Pontifical Council for Culture's "Court of the Gentiles" and Trenitalia, the Italian train company which sponsored the children's ride from Naples to Rome.

Pope Francis' encounter with the school children, who came from Naples as well as outlying areas of Rome, was marked by a joyful informality as he continued his simple question and answer style.

"Is it possible to make a better world?" he asked the children gathered in the atrium of the Paul VI hall on May 31, as they shouted "yes!" in reply.

"Yes! And better than the world I live in?" Pope Francis continued, as his young audience again shouted, "yes!"

"Yes. And to make a better world, how do we do it? With hate? Do we make it with hate?"

Some children stood up out of their chairs to shout, "no!"

"Good, say it, say it louder," he encouraged the, explaining that the task is done "with love. With love. Everyone together, as brothers, struggling alongside the other for love. And for this, I will tell you something: when the Apostle John, who was a very close friend of Jesus - a very close friend - wanted to say who God is, do you know what he said? 'God is love.' It's beautiful."

One little boy presented him with the gift of a clay pot containing dirt from the catacombs in Naples; a young girl brought him a plant.

The Pope used these objects as a theme for his simple catechesis, noting that the earth came from a place of darkness, but the plant grows in the light.

"The darkness is for the light," he explained. "When it is is nighttime, it's completely dark. But we wait for the first (time of) morning, when the light begins. What is more important - this is the question - the darkness, or the light?"

"The light!" his young audience replied enthusiastically.

"The light. Inside of ourselves, always. Because the light gives us joy, gives us hope. And do all of us have that possibility to find the light?"

When the children replied, "yes!" he explained, "because in the light there are good things, and in the light you can do what you told me when you have given me the plant: the fruits help us to make a  world that is…"

"Better!" the children finished for him.

In addition to the plant and dirt from the catacombs, the children and their teachers had prepared a special song for Pope Francis: the traditional Italian ballad, "O Solo Mio," with an added verse of "O Papa Mio."

Cardinal Gianfranco Ravasi, head of the Pontifical Council for Culture, told CNA that the "Court of the Gentiles" program was established as an opportunity for "dialogue between believers and nonbelievers," but he does not want it to remain "only at a high intellectual (or) social level."

He hopes that they will also be willing to confront "the mess, the knots, the obscure things" of life.

Vincenzo Soprano, CEO of Trenitalia, told CNA that he was touched by how hard these children's lives had been, living in the inner-city like atmosphere of Naples. When he asked one child what his favorite part of the trip was, "he answered, 'the landscape along the trip.' Because they have only lived in a small part of Naples."

"It's not for nothing that (today's) symbol was the excavation of the light," Cardinal Ravasi noted, since the small boy who brought up the jar filled with dirt from the catacombs comes from a home with parents involved in drugs, living in terribly impoverished circumstances. His presentation of that gift "profoundly signifies for the children what it is to conserve the interior light."