VATICAN CITY — On the heels of a landmark call by Amazon region bishops for married men to become priests, Pope Francis on Sunday exhorted Catholics to be open to fresh ways of evangelization, saying the church must “open new roads for the proclamation of the Gospel.”

He also cautioned against self-righteousness, in an apparent slap at conservative critics who fear he is weakening the church’s foundations.

Pope Francis

Allowing married men to be ordained in remote Amazon areas with severe shortages of priests would chip away at the church’s nearly millennium-old practice upholding priestly celibacy. It would also help the church compete with evangelical and Protestant churches that have been increasingly winning converts there.

A three-week-long Vatican gathering, or synod, on the special needs of Catholics in that South American region featured a vote by a majority of the more than 180 synod bishops who proposed the ordination of married men with established families to help minister to the region’s far-flung faithful, where some Catholics don’t see priests for months, even years.

Francis expressed gratitude that the bishops spoke with “sincerity and candor.” He has said he will put his response in writing by year’s end.

Addressing the public in St. Peter’s Square, Francis said he and synod participants felt spurred to “leave comfortable shores” in seeking new ways to carry out the church’s core mission to spread the Catholic faith.

Francis has often praised celibacy for priests. If the Argentine-born pontiff embraces the appeal from bishops on his native continent, it is not clear whether that might trigger an erosion of the celibacy rule elsewhere.

Ordaining married men, even in limited circumstances, risks deepening the antipathy in strongly conservative church circles toward Francis, whom they deem to be dangerously progressive.

Francis said he and the bishops “felt spurred to go out, to leave the comfortable shores of our safe ports to sink into deep waters – not in the swampy waters of ideologies, but in the open sea in which the Spirit invites us to throw out the fishing nets,” he said, referring to Gospel writings about fishing for the souls of people.

In prepared remarks, which he didn’t read, he appeared to hint at the appeal for married priests when he encouraged being open to “new things.”

His critics, including so-called traditionalist Catholics, insist the Vatican adheres strictly to centuries-old rules demanding that priests be celibate, unmarried men. But in the first centuries of the church, married men did serve as priests. Even the first pope, St. Peter, hand-picked by Jesus, was married, as were many of the first apostles.

Currently, the Vatican allows married men to become priests in Eastern rite churches. Eager to include converts, it has also allowed married Anglicans to remain priests when they join the Roman Catholic church.

In a possible reference to those who consider themselves guardians of the faith, Francis warned against self-righteousness and what he derided as “self-canonization.”

The idea that mature, married men of “proven virtue” could become priests has been suggested for decades, including during the papacy of St. John Paul II, a darling of conservatives.

But the Amazon synod’s formal proposal was the first official call for it.

Francis might seize that momentum. But he also might tread cautiously to avoid disorienting faithful whose trust in the church hierarchy has been seriously eroded by decades of pedophile priest scandals in many countries.

Italian theologian Marinella Perroni, noting in an interview with Italian daily La Stampa that the ban on married priests became formal more than 1,000 years after the church’s founding, ventured that it could be more than a century before marriage is no longer an impediment to ordination.

Synod bishops also called for the Vatican to revive study of whether women can be ordained as deacons, a lesser role than priests. During Francis’ papacy, a commission to study that prospect produced no action.

Deborah-Rose Milavec, a co-director of Future Church, an advocacy group for progressive change, was cautious about whether there would someday be female deacons, especially since any married priest in the Amazon would probably be selected from the ranks of male deacons.

Francis also echoed environmental concerns by the Amazon bishops.

He lamented that the Amazon’s native peoples had been considered “backward and of little worth,” and denounced those who have despised their traditions and sought to erase their history as well as “occupy their lands and usurp their goods.”

“How much alleged superiority, transformed into oppression and exploitation, exists even today!” Francis said. “The mistakes of the past were not enough to stop the plundering of other persons and the inflicting of wounds on our brothers and sisters and on our sister earth.”