By Dan Merica, CNN

Washington (CNN) – Even though Roman Catholics are the second-largest religious group in the United States, the tradition has seen an exodus of members in recent decades. One in ten Americans is an ex-Catholic.

If ex-Catholics were counted as their own religious group, they would be the third-largest denomination in the United States, after Catholics and Baptists, according to the National Catholic Reporter.

If it weren’t for the infusion of Catholic immigrants, especially from Latin American, the American Catholic Church would be shrinking pretty fast.

A recent study by two college professor tries to get at a simple question: Why are they leaving?

Conducted William J. Byron, a professor of business at St. Joseph’s University and Charles Zech, founder of the Center for the Study of Church Management of Villanova’s School of Business, the anecdotal study conducted in late fall of 2011 processes the opinions of 300 non-churchgoing Catholics in Trenton, New Jersey.

The scholars, working at the request of Trenton’s Catholic bishop, asked parishioners who have drifted away not just why the left, but what church teachings they disagree with and whether they ever truly considered themselves part of the Catholic community.

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Though the study paints a picture of a church with some characteristics that rub people the wrong way, the researchers – both at Catholic schools in Pennsylvania – argue that the study presents new ways in which church leadership can reconcile with ex-Catholics.

"We need a more pastoral approach to people," Zech says. "There are two types of issues that appear. One revolves around church beliefs and frankly those won’t change. But we have to do a better job explaining some of the issue that the church might not change and why that is."

The report is based on one particular diocese, but its authors say it gives a good picture of challenges facing the broader church. "I think the same seven items would show up for the most part," in other areas of the country, Zech says.

The 7 biggest reasons Catholics from Trenton are leaving the church, according to the study:

1. The sex abuse crisis

Byron and Zech asked ex-Catholics to cite their main reason for leaving: “If you could communicate directly with the bishop, what would you say?”

The most common answer: the church’s inadequate response to clergy sex abuse. “The bishop’s refusal to list pedophile priests on the diocesan Web site and his non-support of the effort to lift the statute of limitations for bringing sexual abuses cases forward in the courts” did it for me, one man said, according to the report.

Several respondents said they had been victims of sexual abuse by church leadership.

2. The church’s stance on homosexuality

The second most cited reason for leaving the church was that former worshipers felt homosexuals were unwelcome in the church.

As recently as March 9, Pope Benedict XVI denounced what he categorized as the “powerful” gay marriage lobby in the United States. In the same speech he noted these views would be seen as “countercultural” to young people, but told bishops to not back down to “powerful political and cultural currents seeking to alter the legal definition of marriage."

When those surveyed were asked if there were any religious beliefs in the Catholic Church that troubled them, a number cited views on same-sex marriage. “The church’s view on gays, same-sex marriage, women as priests and priests not marrying, to name a few,” said one respondent, explaining her departure from the church.

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“Hypocrisy,” said one person. “History of discrimination against women, anti-gay stance, unwelcoming attitude.”

William D’Antonio of the Catholic University of America recently published a study called “Catholics in America: Persistence and change in the Catholic landscape.” found that even though the church and the U.S. Conference of Catholic Bishops has come out against homosexual relationships, only 35% of Catholics surveyed said the church’s opinion on homosexuality is “very important.”

The same survey found that 86% of respondents believe a Catholic “can disagree with aspects of church teachings and still remain loyal to the church."

3. Dissatisfaction with the priest

About half of those surveyed in the Trenton report were not supportive of the pastor they had left behind.

According to Byron and Zech, words like “arrogant,” “distant,” “aloof” and “insensitive” were all used by respondents to describe their priest.

4. Uninspiring homilies on Sundays

A number of people responded that homilies, weekly Sunday messages from the priest, did not relate or “speak to” them.

“I stopped going regularly because the homilies were so empty,” one respondent said. “And whenever the church wanted to raise money, they dropped the homily and talked money.”

“I would advise the bishop to make training in public speaking mandatory for every priest,” said another. “They should also be trained in how to relate their homilies to the people and inspire them.”

“As much as I wanted to get involved and expand my faith, there were no clear avenues to do that,” replied one person. “So it was just a place to attend Mass. And because attending Mass was a guilt-ridden obligation, I was always alone in a crowd where I knew no one and no one knew me.”

5. Perception that church hierarchy is too closely tied to conservative politics

Politics was a mixed bag, according to the survey.

Though some people wanted the church to become more conservative – “change the liberal-progressive political slant to a more conservative,” said one person – others responded differently.

“Eliminate the extreme conservative haranguing,” said one person. Another respondent said politics and the church shouldn’t mix: “I feel the church should stay out of politics; it should certainly not threaten politicians.”

6. Church’s stance toward divorced and remarried Catholics

Catholicism’s stance on divorce and remarriage were also highlighted, especially by divorced females.

The churches stance on divorce is closely tied to their stance on adultery. Without getting a marriage annulled, any marriage after a divorce is considered adulterous. Therefore, divorced people who have not had their marriage annulled or remarried are not able to receive Holy Communion.

“Please find a way not to exclude me from the Catholic community,” said one 56-year old divorced female. A 59-year old divorced female said she would tell her bishop to “petition the church to expand its view on divorce.”

In November of last year, Pope Benedict XVI responded to a German bishop who questioned the Church’s teaching on divorce and remarriage. “A pastoral approach which truly wants to help the people concerned must always be grounded in the truth… in the end, only the truth can be pastoral,” the Pope wrote, signaling a reluctance to change church teachings on divorce and remarriage policy.

“Instead of making every Mass a form of humiliation for Catholics who cannot receive communion,” one respondent to the Trenton survey said, “do something like a private blessing at communion time, to include everyone.”



7. The status of women

With the political debate over religious conscience and contraceptive coverage, women’s rights and the church have come to the forefront of debate in American politics. According to the Trenton study, a number of people who have left the church cite a “history of discrimination against women,” as one reason for leaving.

Respondents also took issue with the fact that while other churches allow women to become ordained priests, the Catholic Church does not.

“If the Catholic Church does not change its archaic views on women, it is going to become a religion that survives on the fringe of an open-minded, progressive society,” one person who was surveyed said.