Washington (CNN) Earlier this month, the Trump administration summoned two dozen religious leaders to a private meeting. The mission: to rally support for Neil Gorsuch, Trump's Supreme Court nominee.

According to several participants, White House staffers emphasized Gorsuch's robust defense of religious rights as a judge on the 10th US Circuit Court of Appeals. In one prominent decision , Gorsuch argued that the government should rarely, if ever, coerce the consciences of believers.

Eventually, the conversation turned to Gorsuch's own religious background.

He was raised Catholic but now worships with his wife and two daughters at St. John's Episcopal Church in Boulder, Colorado. Like the city, the congregation is politically liberal. It bars guns from its campus and installed solar panels; it condemns harsh rhetoric about Muslims and welcomes gays and lesbians. And its rector, the Rev. Susan Springer, attended the Women's March in Denver, though not as a form of protest but as a sign of support for "the dignity of every human being."

Springer says St. John's is carrying out the covenant Episcopalians recite during baptisms: to strive for justice and peace among all people. Her congregation, she added, includes liberals, conservatives and all political points in between.

"What binds us together as one body is a curiosity and longing to encounter and know God," she wrote in an email to CNN, "a willingness to explore our own interior selves, and a desire to leave the world in some small way better for our having been in it."

As Gorsuch's Senate confirmation hearings began on Monday, some hardline conservatives have raised concerns about his choice of church.

"Be advised," blared a tweet from Bryan Fischer, a host on the American Family Radio Network. "Gorsuch attends a church that is rabidly pro-gay, pro-Muslim, pro-green, and anti-Trump."

"Is Gorsuch a secret liberal?" asked an op-ed in The Hill, a Washington newspaper.

Another columnist argued that if conservatives complained about Barack Obama's former pastor, the Rev. Jeremiah Wright, shouldn't they also grumble about Gorsuch's?

At the meeting in Washington, held in the Eisenhower Executive Office Building next door to the White House, administration officials encouraged the religious leaders to push back against such questions. St. John's is one of only two Episcopal churches in Boulder, and the other caters to students at the University of Colorado, they said, according to people who attended the meeting. Anyway, Gorsuch should be judged on his judicial opinions, not his pastor's politics, they argued.

Many Catholics and evangelicals agree, pointing to Gorsuch's sterling conservative credentials. He is a lifelong Republican and a member of the Federalist Society, a leading conservative legal organization. He has written a scholarly book arguing against assisted suicide and openly admires the late Antonin Scalia, the justice he would replace, a hero to the conservative intellectual elite.

But in the black-and-white world of partisan politics, Gorsuch's writings and religious life show several strands of gray.

He studied with an eminent Catholic philosopher but attends a progressive Episcopal parish. He has defended the religious rights not only of Christian corporations but also of Muslims and Native Americans. He has thought deeply about morality, but says judges have no right to impose their views on others. He is hailed as the fulfillment of President Trump's pledge to pick a "pro-life" justice, but has no judicial record on abortion itself.

Even Gorsuch's own religion is somewhat of a gray area.

If confirmed by the Senate, would Gorsuch be the high court's only Protestant justice, or its sixth Catholic? His close friends and family offer different answers to that question.

A quiet faith

Gorsuch's father was not conventionally religious, preferring the outdoors to church pews, family members say.

"He showed me ... that there are few places closer to God than walking in the wilderness or wading a trout stream," Gorsuch said at his confirmation hearing in the Senate on Monday.

His mother, Anne, meanwhile, came from a long line of Irish Catholics.

Rosie Binge, Anne's sister and Gorsuch's aunt and godmother, said her parents ferried their seven children to Mass every morning, and dinner was followed by a family recitation of the Rosary.

"I think religion is a big factor in Neil's life," Binge said. "When you grow up with someone so devout, it has to rub off on you."

The three Gorsuch children -- Neil, Stephanie and J.J. -- attended Mass most Sundays and were enrolled in Catholic schools for much of their early educational lives, family members say.

In his speech accepting Trump's nomination to the Supreme Court, Gorsuch briefly alluded to his faith, saying it had lifted him through life's valleys. That was especially true during the early 2000s, said Gorsuch's younger brother, J.J., when their father, David, suffered from an aneurysm and later died, closely followed by his twin sister. Their mother, Anne, died in 2004.

"It was a tough time for the family," said J.J. Gorsuch, who worships at a Catholic church in Denver. "I know that prayer, and group prayer, helped sustain him as well as the rest of us."

After his parents' death, Neil Gorsuch grew close to his uncle, the Rev. John Gorsuch, an Episcopal priest, who died February 15. On a group call following Neil's nomination, family members say, the pastor joked that some of the people on the line were Democrats, but all were proud of his nephew.

At his Senate confirmation hearing on Monday, Gorsuch called his uncle "a hero of mine," and choked back tears as he said, "He gave the benediction when I took my oath as a judge 11 years ago. I confess I was hoping he might offer a similar prayer for me this year. As it is, I know he is smiling."

When the family moved to Washington, where Anne Gorsuch led the Environmental Protection Agency in the early 1980s, Gorsuch attended Georgetown Prep, a Jesuit school in Maryland.

Michael Trent, who has known Gorsuch since they were 14, remembers his close friend as studious but affable, equally at home in the library stacks and outdoors. He kept most of his opinions, including his religious views, private.

"It's important to him, but in the times we've spent together it has not been a big part of the conversation," said Trent, who lives in Marietta, Georgia. "It's just one those quiet things you understand about a person."

Gorsuch is godfather to Trent's two sons, whom he spoils with presents on birthdays and Christmas, Trent said.

Neil Gorsuch with his godson, Matthew Trent.

After college and law school, between stints clerking at the Supreme Court, Gorsuch studied legal philosophy at Oxford University in England, where his dissertation was supervised by John Finnis, a giant in the field and a former member of the Vatican's prestigious International Theological Commission

Among laypeople, Finnis may be best known for his expositions on natural law, an often-misunderstood area of legal and moral philosophy.

At its heart, natural law refers to a body of norms that adherents believe are not created by humans, but instead are revealed through the application of reason, said Richard Garnett, a professor of political science at the University of Notre Dame Law School, where Finnis now teaches.

Because philosophers like Finnis have employed natural law to argue against abortion and same-sex marriage, the field has become controversial, especially among liberals. In 1994, protesters interrupted an address by Finnis at Harvard, calling him a "hatemonger" and "homophobe."

In a speech at Notre Dame in 2011, Gorsuch spoke fondly of Finnis, saying, "I have encountered few such patient, kind, and truly generous teachers in my life."

Some conservatives celebrate Finnis' influence on Gorsuch. But others worry that natural law will become an unwelcome distraction during Gorsuch's Senate confirmation hearings, as it was during those of Robert Bork and Justice Clarence Thomas, both of whom expressed their appreciation for the field.

Gorsuch himself drew on natural law while writing his 2006 book "The Future of Assisted Suicide and Euthanasia." In it, he argued that "all human beings are intrinsically valuable and the intentional taking of human life by private persons is always wrong."

Conservatives who have read the book say it not only offers indications of Gorsuch's views on assisted suicide, but abortion as well.

"It is impossible to come away from this rather remarkable book with any conclusion other than that this is a man who has a very high regard for the sanctity and the dignity of human life," said Timothy Goeglein, vice president for external relations for the evangelical ministry Focus on the Family.

"I am confident that he will be a pro-life justice," said Marilyn Musgrave, vice president of government affairs for the Susan B. Anthony List, an anti-abortion group.

Despite Trump's pledge to pick a "pro-life" justice, Leonard Leo, who advised the president on Supreme Court nominees, said the issue was never explicitly raised during their discussions.

Gorsuch's key opinions on religion In Green v. Haskell County Board of Commissioners, Gorsuch dissented from a decision that forced an Oklahoma town to remove a 10 Commandments monument from the lawn of its courthouse. In American Atheists v. Davenport, Gorsuch joined a minority opinion that argued that a "reasonable observer" would not necessarily view crosses erected on public property in honor of Utah state troopers as a government endorsement of religion. In Abdulhaseeb v. Calbone, Gorsuch argued that a Muslim inmate can claim that his religious rights were violated by an Oklahoma prison that refused to provide halal food. In Yellowbear v. Lampert, Gorsuch argued that a Wyoming prison violated a Native American prisoner's religious rights by refusing to grant him access to the prison's sweat lodge. In Hobby Lobby v. Sebelius, Gorsuch wrote a lengthy defense of a Christian family business who said the Affordable Care Act's contraception mandate impinged on their freedom of religion. In Little Sisters of the Poor v. Burwell, Gorsuch joined the dissent in siding with an order of nuns who likewise refused to comply with the contraception mandate, arguing that it violated their religious consciences.

"Judge Gorsuch wasn't asked about it, and he's not going to make a commitment on it," said Leo, who has taken a leave from his job heading the Federalist Society while he shepherds Gorsuch's nomination through the Senate.

Gorsuch himself cautioned senators against reading too much into his work in moral philosophy when he was nominated to the 10th Circuit Court of Appeals in 2006. "My personal views, as I hope I have made clear, have nothing to do with the case before me in any case," he said. "The litigants deserve better than that, the law demands more than that."

In that regard, Gorsuch said he closely follows the man he would replace on the Supreme Court. In a speech shortly after Scalia's death last year, Gorsuch said the "great project" of the late justice's life had been to argue for a strict separation of powers between judges and legislators.

Lawmakers may appeal to public and personal morality, Gorsuch said, but judges never should. Their job, he said, is to interpret the law, rendering decisions based on what the text says, not what they believe.

Other legal scholars say that's unrealistic. No matter how hard judges try, their personal passions and partisan leanings always seep, even unconsciously, into their decisions.

Episcopalian or Catholic?

When Neil Gorsuch returned from his studies in Oxford, he came home a married man. His British-born wife, Louise, was raised in the Church of England. As the new family settled in Vienna, Virginia, they joined Holy Comforter, an Episcopal parish.

According to church records, the Gorsuches were members of Holy Comforter from 2001 to 2006, when they moved to Colorado. But on membership forms, Neil listed his religion as Catholic, and there is no record that he formally joined the Episcopal Church, said the Rev. Lyndon Shakespeare, Holy Comforter's interim rector.

That's not unusual, Shakespeare said.

The Catholic and Episcopal churches may differ on politics, but their worship services can be quite similar, and a number of Catholics worship at Episcopal parishes without formally changing their religious identity. The churches recognize each other's baptisms and marriages, but the Catholic Church does not regard celebrations of Holy Communion at Episcopal services as valid, experts say.

When the Gorsuch family moved to Colorado, they joined St. John's, where they have been active in Sunday services. Louise is a lay reader, the couple's two daughters likewise assist in the liturgy as acolytes and Neil has been an usher.

Friends and family say Louise Gorsuch has an affinity for the liturgy and music at St. John's, finding in it an echo of her upbringing in the Church of England.

"Many of the hymn texts and musical settings are centuries old, some dating to the earliest centuries of Christianity," said Springer, the church rector. "For people who have been life-long Anglicans, this music ties back to childhood."

Springer declined to speak in detail about the Gorsuches, but in a recent church newsletter she praised Neil as "a broad-thinking" and thoughtful man.

In a statement, the congregation of St. John's echoed that sentiment:

"We know Neil as a man of great humility and integrity, one eager to listen and thoughtful in speaking. These qualities are ones we pray all public servants in any leadership role in our country might possess. We care deeply for Louise and the girls and know them as people of solid faith. We give thanks to God for the presence of this family in our midst."

Springer said she doesn't know whether Gorsuch considers himself a Catholic or an Episcopalian.

"I have no evidence that Judge Gorsuch considers himself an Episcopalian, and likewise no evidence that he does not."

Gorsuch's younger brother, J.J., said he too has "no idea how he would fill out a form. He was raised in the Catholic Church and confirmed in the Catholic Church as an adolescent, but he has been attending Episcopal services for the past 15 or so years."

Trent, Gorsuch's close friend, said he believes Gorsuch would consider himself "a Catholic who happens to worship at an Episcopal church."

Rosie Binge said her family was surprised to see media reports calling her nephew an Episcopalian. "I think once you're a Catholic, you're always a Catholic," she said, before adding with a laugh, "At least he's going to church!"

Binge is right about the Catholic Church.

Once baptized Catholic, a person enters an unbreakable theological communion, even if he or she later worships in a different church, said William Daniel, a canon law expert at Catholic University in Washington, DC.

"We would say that fundamentally such a person is still Catholic, even if they are living out their life as a Lutheran or Episcopalian. We wouldn't confront the person, but if they asked, we would say: Yes, you're still a part of the Catholic Church."

Daniel emphasized that he was not speaking specifically about Gorsuch.

Gorsuch could also call himself an Episcopalian if he meets the church's minimum standards for membership: Being baptized Christian, receiving Holy Communion at least three times a year and supporting the church through prayer and financial donations.

"The intent here is key," said the Rev. Thomas Ferguson, an Episcopal priest and an expert on its relationships with other churches. "If he intends to be an Episcopalian he could certainly be considered one."

This may seem academic, but the religious composition of the Supreme Court is closely watched by many believers. There has not been a Protestant justice on the Supreme Court since John Paul Stevens retired in 2010, and many Protestants eagerly anticipate Gorsuch's confirmation as a religious milestone. Currently, there are five Catholics and three Jews on the high court.

"In the interest of pluralism, it's about time we had a Protestant on the Supreme Court," said Richard Land, president of Southern Evangelical Seminary and a member of Trump's evangelical advisory board.

"Would I be happier if he were going to a more traditional Episcopal Church? Yeah, I'd be happier for him," Land continued.

"But I'm more concerned with his views on the Constitution than where he goes to church."