In his meeting with adoptive families and nuns from the Missionaries of Charity, the order founded by Mother Teresa, John Paul was lavish in praise for her.
After Mother Teresa died in 1997, at 87, after a life spent caring for outcasts in the slums of Calcutta, John Paul waived the customary five-year waiting period to start the process leading to possible sainthood.
"It seems to us that we still see her passing through the world in search of the poorest among the poor, always ready to open new places for charity, welcoming all as a true mother," the pope said. He made no mention of prospects for sainthood.
John Paul decried that, in the face of many children who don't have parents, "there are so many couples who decide to remain without children for reasons not rarely selfish."
At the same time, the pope took to task those who "desiring to have their 'own' child at all costs, go beyond the legitimate help that medical science can assure procreation, pushing themselves toward morally reprehensible practices."
The pope has repeatedly condemned such techniques as in vitro fertilization, insisting that the only way approved by the Catholic Church to have children is sex between husband and wife.
John Paul, while praising the concept of adoption, seemed to be closing the door to that possibility to single people or unmarried couples.
When a family is "solidly joined by marriage, it assures the child that serene environment and that affection, both paternal and maternal, which he needs for full human development."
Italian lawmakers recently wrestled with proposals to allow unmarried people to adopt but decided to leave unchanged the obligation to be married.