With her shy nun's smile and gentle demeanor, Sister Jeannine Gramick seems the most unlikely of gadflies. But, as a new documentary about her ministry to gay Catholics shows, she is fearless in fighting anyone who tries to silence her.

The film, "In Good Conscience: Sister Jeannine Gramick's Journey of Faith," has made the rounds at film festivals from Milan to Kansas City. It recently won the audience favorite award for a documentary at the Philadelphia International Gay and Lesbian Film Festival in Gramick's home town.

The film follows four years of Gramick's three-decade quest to make her church more accepting of gay men and lesbians. It is a quest that began with a question.

"I was a good little nun for many, many years," Gramick says in the film. "Until I met a gay man, and that friendship really changed the direction of my life. The question that Dominic kept asking me was, 'Now Sister, what is the Catholic Church doing for my gay and lesbian brothers and sisters?' "

That was in 1971. Soon after, she co-founded New Ways Ministry, a national research and advocacy center for gay Catholics. She has also written books on gay issues, and consistently challenged church leaders to rethink the theology that condemns homosexual acts as a "grave depravity" and "intrinsically disordered."

The church hierarchy has not been pleased. In 1999, Cardinal Joseph Ratzinger, who heads the Vatican office that safeguards church teaching, the Congregation for the Doctrine of the Faith, issued a gag order on Gramick because she had "caused confusion among the Catholic people" and "harmed the community of the church." For those reasons, Ratzinger ordered, "Sister Jeannine Gramick . . . is permanently prohibited from any pastoral work involving homosexual persons."

Gramick complied with the prohibition, but she continued to speak out for greater tolerance of gay men and lesbians. In 2000, the general superior of her order, the School Sisters of Notre Dame, told Gramick, "You are not to speak or write, by any means whatsoever, on matters related to homosexuality."

Barbara Rick, director of "In Good Conscience," remembers reading in a newspaper article the nun's response to her superior: "I choose not to collaborate in my own oppression."

"I sat straight up in my seat," Rick said in an interview. "Because here was a nun that was a hero to many on this issue. And this muzzling, it was almost medieval."

The filmmaker was also taken by the Gramick's humility.

"She's not just out to bad-mouth the church," Rick said. "She's actually following her conscience, which is a primary Catholic tenet."

Gramick's conscience has led her to join a different order, the Sisters of Loretto; to accept speaking engagements across the world; and to travel to Rome, where she talked her way past sword-bearing Swiss sentries guarding Ratzinger's Vatican office.

For the last four years, Rick's camera was there to document it all.

To young Catholic students, Gramick argues that Scripture, which many point to when denouncing homosexuality, also condones slavery and prohibits "hump-backed priests."

"We hold on" to certain parts of the Bible, she says in the film, "because we use them to justify prejudices that already exist and we're going to use Scripture to back it up."

To gay men and lesbians, she preaches the primacy of conscience and advises them to "not censor yourselves from the things in the church that you have a right to."

In the film, most of Gramick's attempts to buttonhole bishops to talk to them about gay rights fail, and Ratzinger says he is too busy to meet with her and doesn't acknowledge her letters.

The U.S. Conference of Catholic Bishops' Office for Film and Broadcasting, which routinely reviews movies, said it has not yet had a chance to see "In Good Conscience."

Sister Jeannine Gramick's defiance of an order to stop ministering to gays is the focus of a documentary.