The tradition of the Church is not a funerary urn holding the ashes of the past, Pope Francis said Sunday, and nor is a “fundamentalist” nostalgia for a golden age that will never return.

“Tradition is the guarantee of the future and not the keeper of ashes,” the pope told journalists aboard the papal plane returning to Rome from Romania. “It is not a museum. Tradition does not guard the ashes, the nostalgia of fundamentalists, to return to the ashes, no.”

Tradition is rather “the roots that guarantee the tree will grow, flourish and bear fruit,” he said. “All the florid growth the tree produces comes from what it has drawn from the earth,” he added, citing an Argentinian poet.

Francis applied these reflections to emeritus Pope Benedict, whom he visited recently.

“Every time I visit him, I feel it. And I take my hand and I let him talk. He speaks little, slowly, but with the same depth as ever,” he said. “Because Benedict has a problem with his knees, not his head: he has great lucidity and when I hear him speak, I become strong; I feel the ‘sap’ of the roots that comes to me and helps me to move forward.”

“I feel this tradition of the Church that is not a museum piece, no,” Francis continued. “Tradition is like the roots, which give you sap to grow. And you will not become like roots, no. You will blossom, the tree will grow and bear fruit, and the seed will be roots for others.”

“The tradition of the church is always in motion,” he said.

Last month the pope touched on a similar theme, urging Catholics to learn the discipline of “renunciation,” being able to let go of precious traditions for the sake of the gospel.

In the early Church, the disciples of Jesus had to let go of the cherished Jewish traditions they grew up with, Francis said, and this detachment from traditions is a model for today’s Christians.

Moreover, “those first Christians did not abandon things that didn’t count: it was about traditions and important religious precepts that were dear to the chosen people. What was at stake was religious identity,” the pope said.

“For the good of the mission, to proclaim that God is Love to everyone in a way that was transparent and credible, even those human convictions and traditions which are more an obstacle than a help, can and must be let go of,” he said.

“True faith purifies from attachments. To follow the Lord requires walking quickly and to walk quickly you need to lighten yourself, even if it costs,” the pope concluded.