From the pulpit of the Christ Cathedral in Garden Grove, the Rev. Bao Thai delivered a homily on a recent Sunday morning, urging his congregation to vote against Proposition 1, a measure on the Nov. 8 ballot that would enshrine the right to abortion in California’s constitution.

“A steward is entrusted to care for the master’s property until his return,” he preached. “What precious goods has the creator placed in our care? Do they include the innocent and sacred lives of the unborn and children to be born?”

A few weeks earlier, at Good Shepherd Catholic Church in Pacifica, two congregants asked those attending Mass to support the campaign against the “harmful” Prop. 1 with prayers, fasting and money.

Bishops and other clergy from California’s dozen Catholic dioceses and archdioceses Monterey to San Bernardino — have released videos to speak directly to the faithful, sometimes in multiple languages, about their concerns that the initiative would remove all existing restrictions on abortion in the state.

“Life is precious from the very moment of conception,” the Rev. Michael Mahoney of Our Lady of Angels Parish in Burlingame said in a recent message filmed at the site of a future parish garden, where he encouraged families to take home “No Prop 1” signs for their yards.

Fundraising by the opposition campaign is trailing significantly, in a state where a clear majority of adults regularly express support for abortion rights. So the success of a long-shot effort to defeat Prop. 1 may rest primarily on outreach by faith leaders and their ability to mobilize followers from the pews to the polls.

About a month before Election Day, as mail ballots are set to begin arriving at the homes of every registered voter in California, officials across several major denominations are tapping into their networks of worshippers to get the word out against the abortion measure. Meanwhile, some conservative faith-based political groups are organizing voters to involve their churches in the campaign. Though not legally allowed to endorse partisan candidates because of their tax-exempt status, churches can advocate on issues, including ballot measures.

The most significant push so far has come from the Catholic Church.

An August poll by the UC Berkeley Institute of Governmental Studies found 71% of registered voters were prepared to support the measure.

Kathleen Domingo, executive director of the California Catholic Conference, the state public policy office of the church, said even Catholic leaders are divided on whether they have a real chance to defeat Prop. 1. But they are undertaking a serious organizing effort regardless, she said, because it also presents an opportunity to get more people involved in their regular activities serving needy women, children and families.

“Win or lose, there’s benefit in the process,” she said. “It’s never a bad thing to get people thinking about vulnerable people in their communities.”

The main opposition campaign to Prop. 1 stresses that its coalition is broader than faith-based organizations.

Opponents raise concerns that the broad language of the initiative would override all existing restrictions.

Yes on Proposition 1 spokesperson Molly Weedn said the characterization that the measure would remove all abortion restrictions in California is false. “That is a lot of misinformation and fear-mongering from the opposition,” she said. “The initiative is simply going to take existing law and add it to the constitution.”

Catherine Hadro, a spokesperson for California Together, No on Proposition 1, said it is targeting its communications to all Californians.

“We know this is a message that resonates with Californians, no matter their faith,” she said.

But spreading that message through traditional electoral methods, such as digital advertising and mailers, has been challenging. The campaign has reported raising $1.1 million so far, most of it in the final week of September.

A separate effort, led by groups affiliated with the evangelical Christian movement, has raised about $73,000.

Proponents of Prop. 1, by comparison, have reported $11.8 million in contributions.

The measure was also recently endorsed by Catholics For Choice, a national nonprofit that advocates for abortion access and other policies. In a statement, President Jamie Manson said “the bishops’ radical anti-choice views are wildly out-of-step with the majority of the people in their own pews.”

“This faithful pro-choice majority supports abortion access because it aligns with our Catholic social justice values of human dignity, justice for the poor and marginalized, and religious freedom — not in spite of our Catholic faith, but because of it,” Manson said.

CalMatters reached out to Archbishop Salvatore Cordileone of the Archdiocese of San Francisco and Bishops Jaime Soto of the Diocese of Sacramento, Kevin Vann of the Diocese of Orange and Daniel Garcia of the Diocese of Monterey, who were identified in a July memorandum as the leadership team for the Catholic campaign against Prop. 1.

Representatives for Soto and Garcia did not return numerous calls and emails. Representatives for Cordileone and Vann declined because they were told to direct all inquiries through Domingo of the California Catholic Conference.

Domingo said the church’s political engagement has been more extensive in this election because preventing abortions of “viable unborn children” is “something that’s dear to us.”

Some other faith communities in the state have also begun outreach against Prop. 1 through their networks, though none is yet as extensive as the Catholic Church’s campaign. Many of the leaders recognize that they face long odds to stop the measure, but say they feel a moral imperative to fight to uphold what limits still remain on abortion in California.

Separately from the official opposition campaign, a handful of religiously affiliated groups have launched websites to organize against Prop. 1.

Mahoney, the priest in Burlingame, said the question of protecting life that drives the Catholic Church is much larger than this initiative.

The debate over abortion obscures other efforts to get women the resources they need to carry their pregnancies to term and take care of their babies after birth, he said. His parish collects baby clothes and other supplies for young mothers who cannot afford them.

With Prop. 1 appearing likely to pass, Mahoney, who preached against the measure at a recent Sunday Mass, said his ultimate goal is to shift the entire notion of what it means to give women a choice. Rather than pouring hundreds of millions of dollars into shoring up abortion providers, he said California should direct that money to programs that support poor mothers or to expanding access to adoption.

“What we are trying to do is to say, ‘Look, there are options,’ ” Mahoney said. “I would love to change the conversation, because we have no chance whatsoever” to defeat Prop. 1.