PHILADELPHIA — Likening the world today to a giant supermarket with a plethora of choices but an impersonal feel, Pope Francis urged his bishops to embrace change and work within it to connect with young people.

He also urged the bishops to not merely harp on doctrine, but also to preach positively about the benefits of marriage and family life.

“A Christianity which ‘does’ little in practice, while incessantly ‘explaining’ its teachings, is dangerously unbalanced. I would even say that it is stuck in a vicious circle,” he said. “A pastor must show that the ‘Gospel of the family’ is truly ‘good news’ in a world where self-concern seems to reign supreme!”

Francis did not mention same-sex marriage, but US bishops have cited that, as well as high divorce rates, contraception, and abortion as serious threats to the family.

Pope Francis’ remarks to bishops taking part in the World Meeting of Families

But the majority of his speech was focused on encouraging his bishops to accept the realities of life today.

“Christians are not immune to the changes of their times,” Francis said. “This concrete world, with all its many problems and possibilities, is where we must live, believe, and proclaim.”

The pope’s remarks came to 300 bishops from around the world gathered in Philadelphia for the World Meeting of Families and was delivered shortly after he met with a group of sexual abuse victims. Speaking off the cuff, Francis called the victims “true heralds of mercy,” and he promised that “all those responsible are held accountable.”

Returning to his theme of flexibility, the pope encouraged his bishops to recognize that despite the tendency of young people to be obsessed with “running after the latest fad, accumulating friends on one of the social networks,” that lack of personal contact can lead to “a kind of impoverishment born of a widespread and radical sense of loneliness.”

It is, he said, a “loneliness with fear of commitment in a limitless effort to feel recognized.”

The morning after delivering an enthusiastic, off-script sermon about the beauty of family life at the Festival of Families Saturday nignt, Francis used an extended metaphor almost everyone can relate to – grocery shopping – to explain the challenges of ministering to families today.

In the old days, the pope said, society was like a neighborhood store.

“The products may not have been cleverly displayed, or offered much choice, but there was a personal bond between the shopkeeper and his customers,” Francis told the bishops. Then there’s the giant supermarket, he said, with a multitude of choices but leading to a breakdown of trust and neighborly bonds.

“Today’s culture seems to encourage people not to bond with anything or anyone, not to trust,” Francis said. “Consuming relationships, consuming friendships, consuming religions, consuming, consuming. Whatever the cost or consequences. A consumption that does not favor bonding, a consumption which has little to do with human relationships.”

The pope said pastors must resist the temptation to say things were better in the old days and be willing to engage people where they are, not blame them for the way things are today.

“Are today’s young people hopelessly timid, weak, inconsistent? We must not fall into this trap,” Francis said.

Mindful that the median age of marriage continues to rise and the number of children continues to drop in the United States and Europe, Francis reiterated his call for young people to have the courage to make long-term commitments, saying true happiness can only be found that way.

“Many put off marriage while waiting for ideal conditions, when everything can be perfect. Meanwhile, life goes on, without really being lived to the full,” he said. “For knowledge of life’s true pleasures only comes as the fruit of a long-term, generous investment of our intelligence, enthusiasm, and passion.”

Looking up from his remarks, Francis joked that mothers could help by refusing to pamper their adult sons, a phenomenon especially prevalent in Italy.

He recalled a mother saying to him, “My son is 34 years old and he’s not getting married. I don’t know what to do.”

The pope’s reply: “I say, don’t iron his shirts anymore!” The crowd laughed.

“We have to encourage the youth to take that risk [to commit to marriage], because they need to move toward fruitfulness,” Francis said.

The pope called on bishops to move away from stale denunciations about the state of the world, and instead engage with young people.

“We need to invest our energies not so much in rehearsing the problems of the world around us and the merits of Christianity, but in extending a sincere invitation to young people to be brave and to opt for marriage and the family,” Francis said.

Francis again repeated his call for pastors to be with their people — or to smell of sheep, as he’s memorably put it in the past.

“A pastor watches over the dreams, the lives, and the growth of his flock,” he said. “Only one capable of standing in the midst of the flock can be watchful, not someone who is afraid of questions, contact, accompaniment.”

In his talk to families last night, Francis joked that sometimes people question what celibate priests and bishops can really contribute to a discussion about family life, and he touched on that topic again Sunday.

“A good pastor renounces the love of a family precisely in order to focus all his energies, and the grace of his particular vocation, on the evangelical blessing of the love of men and women who carry forward God’s plan of creation,” he said, “beginning with those who are lost, abandoned, wounded, broken, downtrodden, and deprived of their dignity.”

Speaking off script, Francis said the first job of a bishop is to pray, the second is to preach, and “if you have time, you do the rest.”

“Our ministry needs to deepen the covenant between the Church and the family,” Francis said. “Otherwise it becomes arid, and the human family will grow irremediably distant, by our own fault, from God’s joyful good news, and they’ll go to the local store that is most popular and they’ll buy the product they desire at the moment.”