VATICAN CITY (CNS) — Treating all other people as brothers and sisters “is not fashionable now,” Pope Francis said, but it is a clear “calling card” of a Christian.

“We know that brothers and sisters often argue and fight over many things, but even when that happens, they know how to keep alive that search for a good that cannot prevent peace and harmony between them,” Pope Francis said April 12, meeting members of the Confraternity of Nuestra Senora de la Cinta (Our Lady of the Ribbon) from Tortosa, Spain.

The group was celebrating its 400th anniversary as an association dedicated to promoting devotion to Mary, supporting the church and serving the poor in Tortosa.

Belonging to the group, the pope said, is not just about keeping a part of Catalonian history alive; “You call yourselves brothers and sisters, and by doing so you reveal the fundamental reality of our lives: we are all children of God.”

In a world that seems increasingly divided, the pope said, it is not enough for Christians to call themselves brothers and sisters, they must do the hard work of acting like they really are children of the same God.

And, he said, a Catholic association also must keep intact the “bond of charity that, as brothers and sisters, unites them with their bishop and, through him, with the pope.”

“Looking at the example of Mary, we are called to bring that sense of fraternity to all corners of society,” he said, working to ensure that “the church is a home, a family, a place of welcome and love in which everyone, especially the poor and marginalized, can feel a part and never see themselves excluded or rejected.”