CNN  — 

Hinting that changes could be coming to the Catholic Church, Pope Francis asked a large crowd to pray for God to make miracles out of ideas that some believers might consider “impure” or even “threatening.”

Several hundred thousand pilgrims thronged to see the popular pontiff preach Monday at Los Samanes Park in Guayaquil, Ecuador, according to estimates provided by Ecuadorian officials. Waving flags from several South American nations – including Argentina, the Pope’s homeland – the crowd cheered Francis like a native son.

Monday is the first full day of Francis’ weeklong trip to Ecuador, Bolivia and Paraguay, three of the smallest and poorest nations in South America. In addition to the Mass, Pope Francis is expected on Monday to have tea with Ecuadorian political leaders, pray with a community of Jesuits and visit a cathedral in the capital city of Quito.

Before the Mass, the Pope visited a shrine and prayed with elderly Catholics and sick children.

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In his homily, or sermon, the Pope referred to a highly anticipated meeting of bishops to be held in Rome this October. The Catholic leaders are expected to discuss changes to several controversial areas of church teaching, including divorce and homosexuality.

The bishops will “consider concrete solutions,” Francis said, “to the many difficult and significant challenges facing families in our time.”

“I ask you to pray fervently for this intention,” the Pope continued, “so that Christ can take even what might seem to us impure, scandalous or threatening, and turn it … into a miracle. Families today need miracles!”

One proposal for the synod would remove the ban on divorced and remarried Catholics receiving Holy Communion. But several leading conservative bishops argue that the church can’t change teachings on marriage that originate with Jesus.

At a preliminary meeting last October, conservatives also scuttled an early draft report that mildly praised same-sex relationships and said gays and lesbians have “gifts to offer” the Christian community.

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While lightly touching on politics, Francis focused his homily Monday mainly on family life, calling it the backbone of a moral society.

“The family is the nearest hospital, the first school for the young, the best home for the elderly,” Francis preached. “The family constitutes the best ‘social capital.’ It cannot be replaced by other institutions.”

“The family is also a small church” the Pope continued, “which, along with life, also mediates God’s tenderness and mercy. In the family, we imbibe faith with our mother’s milk.”

Apparently veering off script, the Pope said his mother was sometimes asked which of her five children was her favorite. They are like the five fingers of a hand, Francis recalled his mother replying. If pinched, each one hurts the same.

Today, many families are suffering, the Pope said. To illustrate his point, he drew on the day’s Gospel reading, Jesus’ turning of water into wine at the wedding in Cana.

“Wine is a sign of happiness, love and plenty,” Francis said. “How many of our adolescents and young people sense that these are no longer found in their homes? How many women, sad and lonely, wonder when love left, when it slipped away from their lives? How many elderly people feel left out of family celebrations, cast aside and longing each day for a little love?”

More than 425 million Catholics live in Latin America, according to a 2014 study by the Pew Research Center. That’s nearly 40% of the world’s total Catholic population.

But Catholics in nearly every country, including Ecuador, Bolivia and Paraguay, have fled the church in recent decades for other faiths, or no faith at all.

Later this week, Francis will take side trips to a home for the aged run by nuns, a meeting of grass-roots political activists and one of the continent’s largest prisons in Bolivia, as well as a slum and children’s hospital in Paraguay.

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