They’ve even created prayers for “safe migration” to be said out loud by the congregation during Mass — all in hopes of persuading parishioners to support what they call a humanitarian cause.

However, it’s unclear how the message has been translated from the church pews to the halls of power in Washington.

That’s why church leaders are taking a more aggressive approach starting Sunday at Masses held throughout the country.

Unlike a “Justice for Immigrants” program conducted in 2006-2007, this time church leaders are urging Catholics to call, write and email their congressional representatives, even providing prewritten letters and electronic postcards. Congress returns from its summer break Monday, and although an immigration bill passed the Senate, it faces tough opposition, mainly from Republican lawmakers, in the House.

Kevin Appleby, director of immigration policy at the U.S. Conference of Catholic Bishops, said the latest immigration overhaul campaign is larger, bolder and a more unified national effort than in years past.

“We learned some lesson from 2006, 2007,” Appleby said. “You really have to mobilize constituents and voters in order to succeed.”

Polls show that there is broad support among Catholics for immigration reform, Appleby said. The challenge is getting those people to take action.

“Translating the support to action is the goal,” he said.

On Sunday, Catholic dioceses across the country will start holding events about the need for an immigration overhaul, Appleby said.

The conference’s Committee on Migration is urging bishops throughout the country to address immigration at Mass, providing them with talking points and suggestions for homilies, bulletin inserts and pulpit announcements — all available via the Internet.

“We’ve urged the bishops to focus on this time frame,” Appleby said of the month of September. “It’s a critical time. We need to get the Senate bill through to the House. It needs a push. We’re doing everything right now to keep the pressure up.”

In June, the Senate passed a comprehensive immigration bill that would provide a pathway to citizenship for an estimated 11 million people living in the country illegally. The bill also calls for a $46-billion border security package. However, it remains unclear whether the bill will ever be taken up in the House.

Archbishop José Gomez of Los Angeles, chairman of the Committee on Migration, is strongly urging all priests in his diocese to focus on immigration reform in Sunday’s Mass. Other church leaders have staged pilgrimages and some have met or plan to meet with decision-makers in Washington to press their cause.

The material made available by the bishops conference emphasizes biblical teaching on caring for the unfortunate and oppressed. For example, the bishops quote a number of passages from Scripture, such as Exodus 23:9:

“You must not oppress the stranger; you know how a stranger feels, for you lived as strangers in the land of Egypt.”

A passage from Isaiah (10:1-2) takes aim at lawmakers: “Woe to the legislators of infamous laws, to those who issue tyrannical decrees, who refuse justice to the unfortunate and cheat the poor among my people of their rights, who make widows their prey, and rob the orphan.”

The bishops even provided examples of intercessions, in which a reader makes an appeal and the congregation responds. An example: “For unaccompanied migrant children, that they may be protected from all harm and reunited with loving families, we pray to the Lord.”

Respondents then follow with “Lord, hear our prayer.”

The Catholic Church isn’t the only denomination pushing for a revamping of immigration laws. Evangelicals, Episcopalians, Baptists and other religious groups have launched similar campaigns.

However, some parishioners may not take well to politicking from the pulpit. Appleby acknowledged that not all Catholics will be on board.

“It certainly can be a divisive issue,” he said. “One of the goals of the campaign is to educate Catholics on the issue.”

Bishop Gerald F. Kicanas of Tucson says he will not focus Sunday’s Mass on immigration because he believes the timing is premature.

He says debate over military action in Syria and the looming budget battle will probably take precedent over immigration for lawmakers after they return from recess.

Kicanas plans to appeal to his congregants and join forces with leaders outside of the Catholic Church to push lawmakers on an immigration overhaul sometime in October or November.

“It can’t just be a religious voice, but all of us together have to stand together and say, ‘Now is the time,’” Kicanas said. “Arizona is in the center of this whole immigration question…. We can’t let this moment pass again. We can’t let this opportunity pass, and we need to encourage others — help people speak up.”

cindy.carcamo@latimes.com