(CNN) The path from analytic philosophy to the Episcopal Church is not especially well traveled. But then, Peter Paul Buttigieg's search for God contains a few crooked lines.

Not that he necessarily wants to discuss it.

"I was reluctant to talk about (religion) for a long time," he told CNN in a recent interview. "There's Scripture on this, you know. Jesus said, 'When you pray, be not as the hypocrites are, standing in the synagogues and street corners.'"

But as a presidential candidate Buttigieg says he's engaged in a fight against a battle-tested religious right that has perfected the use of religion as political weaponry. For too long, he said, Democratic politicians have ceded the territory, simply "checking the faith box" as if it were a line on their resumes.

"Because my party's been so allergic to religious language, we've forgotten that people need to be made aware of their choice," Buttigieg told CNN.

"I've got to speak up, if only to point out the hypocrisies of those now in power," he added. "Time will tell whether that's smart politically or not."

Thus far, it seems to be working. Progressives, particularly LGBT Christians, have cheerfully circulated his critiques of the religious right and lauded the gay Christian's candidacy as a watershed moment for a community long shunted to the margins of church life.

"The natural weapon against a gay man is religion," said the Right Rev. V. Gene Robinson, the first openly gay bishop in the Episcopal Church, who has become a confidant to Buttigieg. "By appropriating religion and being an authentically Christian person, he has robbed the opposition of using that weapon against him."

A candidate on the attack

Buttigieg, 37, was raised in one of the country's most Catholic cities: South Bend, Indiana, home to the University of Notre Dame, where his parents were professors. At the age of 29, he was elected the city's mayor. He's a Rhodes scholar, a military veteran, a married gay man and a Democratic candidate for president of the United States.

He's also an active Episcopalian, whose search for meaning -- and the Almighty -- has taken a few unusual turns.

The son of a former Jesuit, he credits Catholicism with awakening his moral conscience, but the baptized Catholic says he did not consider participating in the church as an adult because he is gay. He can be reticent about the details of his faith but has made morality a centerpiece of his campaign for president. He delivers Bible-based jabs with the earnestness of an altar boy but has closely studied how religious rhetoric can shape civil society.

Perhaps most paradoxically, he would seem to be the Democratic candidate most susceptible to religion-based political attacks, and yet he has been the most willing to deliver them.

Buttigieg speaks to a gathering of the National Action Network, a civil rights group, on April 4 in New York.

Buttigieg has not escaped the condemnation of evangelicals like Franklin Graham, who has called on the candidate to repent for his homosexuality. But thus far, the millennial mayor has given as well as he's gotten.

At a CNN debate in July, Buttigieg blasted "so-called conservative Christian senators" for blocking a bill to raise the minimum wage "when Scripture says that whoever oppresses the poor taunts their maker."

But some conservative Christians have pushed back hard, especially after Buttigieg asserted that applying Christianity to politics " is going to point you in a progressive direction ."

"Progressive Christianity necessitates replacing Christianity with an entirely new religion," R. Albert Mohler, president of the Southern Baptist Theological Seminary in Louisville, Kentucky, wrote in a recent column

"Mayor Pete is just the latest prophet of this new religion. He won't be the last."

A religious education

Buttigieg says his parents were not religious, though his father studied to become a Jesuit for a time.

"I don't know exactly what happened," Buttigieg said with a laugh, "but somewhere in the 60s, he became not a Jesuit and started on the path toward being my father."

Born in Malta, Joe Buttigieg, who died in January, was a beloved if sardonic member of the English faculty at Notre Dame, friends say. "Captain Extrovert," one faculty member called him. His last words were "it's been a good trip," according to his obituary in the South Bend Tribune

Buttigieg's Indiana-born mother, Anne Montgomery, 74, is a linguist who taught at Notre Dame for 29 years.

Even in a non-religious family, Buttigieg was constantly exposed to Christianity through the influence of the university and its faculty, who gathered around the family's table to debate the latest news and academic theories.

Buttigieg attends a community-building event hosted by Christ Temple Apostolic Church on June 29 in South Bend, Indiana.

"In South Bend people are always talking about religion," said Meghan Sullivan, who befriended Buttigieg while both were Rhodes scholars in England.

"It's the topic every morning at the gyms and every evening at the bars," added Sullivan, a professor of philosophy at the University of Notre Dame. "Pete was steeped in a culture of deeply intellectual Christianity."

Buttigieg's religious education deepened at St. Joseph High School, a Catholic school in South Bend.

"At St. Joe, we were brought up not only to learn Church doctrine on matters like sexuality and abortion, but also to understand the history of the Church as a voice for the oppressed and downtrodden," Buttigieg wrote in his memoir, "Shortest Way Home."

The teenager experienced a moral awakening in government class, Buttigieg writes, while watching a film about St. Oscar Romero, an archbishop from El Salvador who was assassinated by right-wing militants while celebrating Mass. The school's monument to aborted fetuses provided another reminder of the intersection of religion and politics, he writes.

Patrick McCurry, who taught Buttigieg in a class on morality, remembers him as a brilliant and grounded young man with a keen interest in philosophy and theology.

"I knew within a week of meeting him that he was the smartest human I had ever met," McCurry said in a recent interview. "He was super curious and engaged and thoughtful."

Buttigieg said he tried also to learn New Testament Greek, through an independent study with a "very patient teacher," but it didn't last very long.

Buttigieg greets the Rev. William Barber as he attends a protest against the Trump administration in front of the White House on June 12, 2019.

Buttigieg continued his study of religion at Harvard University, where he was a protege of Sacvan Bercovitch, an esteemed scholar of American Puritans. Bercovitch's work examined the sway Puritan sermons held over American culture and politics, a theme that Buttigieg echoed in his senior thesis.

That thesis traces a long line between a 1670 Puritan sermon that urged Americans to leave home and "civilize the wilderness" all the way to the country's Cold War "insistence on invading Vietnam to 'save' it from godless Communism," Buttigieg wrote.

Beyond academics, Buttigieg says he would occasionally attend services at Harvard's Memorial Church, where he would hear the famed preacher and scholar Peter Gomes expound on progressive Christianity.

"I began to understand the range of Christian traditions beyond the Catholicism I was steeped in at South Bend," he said.

The young scholar also kept a close eye on American politics, writing columns in the Harvard Crimson that urged liberals to seize the moral high ground from conservatives.

A spiritual awakening in England

Buttigieg's search for God began in earnest in Oxford, England, where he studied economics, politics and analytic philosophy on a Rhodes scholarship. It was a "decidedly atheistic" program, said, and the young scholar found it convincing in many ways.

Still, something was lacking. Buttigieg had long been fascinated by the moral and intellectual aspects of religion, but now spirituality began to beckon.

"The more versed I became in analytical philosophy, the more I became aware of the limits of what you can access through analysis and reason," he said. "And I think that's what opened up a personal spiritual search that led me to a lot of chapels and churches around Oxford."

By the time he was an adult, Buttigieg has said, he no longer considered himself Catholic. Instead, he began to explore Anglicanism, a branch of Christianity that broke from the Catholic Church during the English Reformation.

"I found myself going to services at Christ Church, which happened to be across from my college," Buttigieg told CNN in April , "and found in that very simple liturgy a way to begin to organize my spirituality."

Buttigieg and civil rights leader Rev. Al Sharpton pray before a lunch meeting at Sylvia's Restaurant on April 29, 2019 in New York City.

That style of liturgy often means contemplative music, not Christian rock; organs instead of guitars -- or, most preferable of all, silence -- and time to think. More often drawn to moral questions than metaphysics, Buttigieg has a restless curiosity, friends say, that extends to his spiritual life.

"If he thinks there is something interesting under the surface, he won't really stop until he has taken it apart," said Sullivan, who emphasized that she was speaking as a friend and not a representative of Notre Dame.

"He loves to talk about the intellectual side of faith with anyone, but he's guarded with most folks about his feelings and personal life, so you really need to get to know him to connect with the faith side."

After returning to the United States from England, Buttigieg briefly attended a Norwegian Lutheran Church in Chicago, where the sermons were delivered in a language he only partly comprehends.

"Sometimes, understanding only part of a sermon is better," he said with a laugh.

A safe place for Pete

Around 2010, Buttigieg moved back to South Bend, where he planned to run for Indiana State Treasurer, and began attending services at the Cathedral of St. James.

Even then, he said, he still wasn't sure how religion fit into his life. He often sat quietly in a back pew, recalls the Very Rev. Brian Grantz, the cathedral's rector.

The cathedral is part of the Episcopal Church, the American branch of Anglicanism. Considered the "church of the establishment" for much of American history -- 11 US presidents have been Episcopalian -- the church of late has been known as a forerunner of progressive theology.

In 2003, the church elected Robinson as its first openly gay bishop, and a decade later it voted to allow same-sex marriages

Pete Buttigieg at the June 29 event hosted by Christ Temple Apostolic Church in South Bend.

Buttigieg has said that he was drawn to the Cathedral of St. James because "takes seriously that it's urban, it's part of a city."

The 250-member congregation, a mix of downtown South Bend residents and Notre Dame graduate students, was also a place where a young man who was not yet open about his sexuality could feel welcome, Grantz said.

"We don't hang a rainbow flag out front, but we have always been a safe place for people who need it, and I think we became a safe place for Pete."

Asked if the Episcopal Church's welcome of LGBT Christians was a factor in his decision to attend St. James, Buttigieg said he isn't sure.

"I suppose it might be one reason I didn't look for a Catholic church, even though that was the tradition I knew best," he said. "Just the knowledge that there would be that conflict the moment I crossed the threshold."

Love and marriage in South Bend

Buttigieg still attends services at St. James when he's not on the road, Grantz said. Several years ago, the mayor took Grantz up on an offer to preach the Sunday sermon. Neither remember the exact topic, but Grantz said Buttigieg acquitted himself well, clearly explaining the Gospel's lesson.

"And to my absolute disgust, did it totally without notes," Grantz said with a laugh.

Buttigieg announced his campaign for president on Palm Sunday, and attended services that morning at a Presbyterian church in South Bend that lent its sanctuary to St. James during repairs. It was the 8 a.m. service, for which attendance is often sparse, he said.

But on that Sunday it was filled with Episcopalians from around the country who had traveled to South Bend to attend his campaign launch. A little girl from the congregation gave him a palm frond she had woven for the service, Buttigieg recalled. It was in his pocket when he announced his run for president.

Buttigieg kisses Chasten Glezman following their wedding on June 16, 2018, outside the Cathedral of St. James in South Bend.

In June 2018, Buttigieg and his husband Chasten Glezman were married in St. James. The readings included including a passage from the Supreme Court decision legalizing same-sex marriage and an excerpt from Jesus' Sermon on the Mount.

In the excerpt, Jesus urges his followers not to "hide their lamps beneath a bushel," but to be the salt of the earth and light of the world. "Let your light shine before others," he says, "that they may see your good deeds and glorify your Father in heaven."

Buttigieg said the Scripture was a favorite of Glezman's grandmother and provided a spiritual roadmap of sorts for the new couple.

"It reflected our desire that our marriage be good and useful for others," he said, "that you take something like love and hope that it lights up, not only your life, but that of others."

The scene in the cathedral was a wedding, not a political event. But it's tempting to wonder if the Scripture signaled a shift not just in Buttigieg's personal life, but his public career as well. No longer would his Christian faith be a private matter.