"Parents are called to pass on to their children the awareness that life must always be defended," Pope Francis wrote in a message to people joining in the Brazilian Catholic Church's celebration of Family Week, which began Aug. 11.

The Pope returned to his condemnation of the "throwaway culture," something he spoke against several times during his July 22-28 visit to Brazil. He had said that modern cultures tend to treat even human lives as disposable, pointing to the way people, societies and even governments tend to treat both the young and the old.

In his message for Family Week, he said parents have a responsibility to fight that disposable culture by teaching their children that human life, "from the womb," is a gift from God. New life ensures the future of humanity, he said, while older people -- especially grandparents -- "are the living memory of a people and transmit the wisdom of life."

The Pope also charged married Catholic couples and their children with the task of recognizing they must be "the most convincing heralds" of the beauty and grace of Christian marriage.