ABOARD THE PAPAL AIRPLANE (CNN) -- Pope Francis said Monday that he will not "judge" gays and lesbians -- including gay priests -- signaling a shift from his predecessor and offering another sign that the new pope is committed to changing the church's approach to historically marginalized groups.
"If someone is gay and he searches for the Lord and has good will, who am I to judge?" he said in a wide-ranging news conference aboard the papal plane.
Though answering a question about the so-called gay lobby at the Vatican, the pope's remarks seemed to signal a change in tone, if not in teaching, in the church's stance toward gays and lesbians more generally.
The pope was flying back to Rome from Brazil, where he spent the past week celebrating World Youth Day, an international Catholic event that drew millions.
Taking questions from reporters aboard the plane, the pope addressed nearly every hot-button issue facing the Roman Catholic Church: its alleged "gay lobby," Vatican bank corruption, the role of women, abortion, homosexuality and his own personal security.
But it was the pope's remarks on homosexuality -- the head of a 1 billion-member church saying that he will not judge gays -- that caused the widest stir.
"Pope Francis' brief comment on gays reveals great mercy," said the Rev. James Martin, a Jesuit priest and editor at America, a Catholic magazine based in New York.
Martin noted that Francis also showed "greater compassion for divorced and remarried Catholics, a group that has long felt marginalized in the church, and called for a 'deeper theology' on the role of women in the church."
"Today Pope Francis has, once again, lived out the Gospel message of compassion for everyone," Martin said.
The pontiff spoke on the record for an hour and a half in the back of the plane that was carrying him back to Italy after his first international trip as pope to Brazil, where he was greeted by massive, frenzied crowds at every turn.
"I'm happy. It has been a beautiful trip, spiritually speaking; it has been good to me. I'm tired enough but with a heart full of joy," he said.
On Sunday, the mayor's office in Rio de Janeiro said more than 3 million people came to Copacabana Beach for a morning Mass with Francis, who was in Brazil for the weeklong World Youth Day celebration.
Security issues plagued the trip because of Francis' immense popularity as the first Latin America pope. His arriving motorcade was mobbed after a wrong turn, prompting the Brazilian military to raise the trip's security level to "high risk" and send in reinforcements to protect the pontiff, who insisted on being close to the people.
"There is always the danger that there is the crazy person, and we never know what he or she will do," Francis said. "But to create a safety barrier between the bishop and its people is insane. And I'm outside this security. I prefer the risks of the madness outside, to be close to the people."
On the 'gay lobby' and homosexuality
The pope addressed the issue of an alleged "gay lobby" within the church. Hints that the Holy See contained a network of gay clergy surfaced last year in reports about a series of embarrassing leaks to Italian journalists.
The "Vatileaks" scandal factored in Pope Emeritus Benedict XVI's shocking decision to resign this year, according to some church experts, as it impressed upon the 86-year-old pontiff that the modern papacy requires a vigorous and watchful presence.
"There's a lot of talk about the gay lobby, but I've never seen it on the Vatican ID card!" Francis said.
"When I meet a gay person, I have to distinguish between their being gay and being part of a lobby. If they accept the Lord and have goodwill, who am I to judge them? They shouldn't be marginalized. The tendency (to homosexuality) is not the problem ... they're our brothers."
The problem, he said was, lobbies that work against the interest of the church.
In 2005, during Benedict's papacy, the Vatican issued directives barring from the priesthood men "who are actively homosexual, have deep-seated homosexual tendencies, or support the so-called 'gay culture.' "
Francis' brief remarks seem to signal a sharp shift from that policy.
The pope also spoke out about the role of women in the church, saying it needs to be deeper and not end. But he brushed aside the possibility of ordaining women as priests, saying the church had spoken on the matter: "The church says no. That door is closed." He did say that more work needed to be done theologically on the role of women in the church.
Pope watchers have noted that Francis said little to nothing about abortion on his trip to Brazil. Abortion is illegal in Brazil, except for cases in which the health of the mother is
at risk. Laws were recently changed to allow abortions in cases in which the child would be born with certain life-threatening birth defects.
The pope said he had nothing to say on the trip about abortion because the church teachings against it were clear and this trip was the time for "positive" news.
"I believe this is a time of mercy, a change of epoch," the pope said when asked about divorce. He said the group of eight cardinals tasked with reform will explore the issue of whether divorcees can receive Communion, which they are currently barred from doing.
On the Vatican Bank
The pope conceded he was unsure what to do with the Vatican Bank, which is known by its acronym IOR.
"Some say that it would be better if it were a bank, others say that it should be a foundation. Other say to shut it down. These are the suggestions going around. I don't know. I trust the commission's members that are working on the IOR. But I wouldn't be able to tell you how this story is going to end."
And as for what was in the black leather bag he carried onto the plane? A razor, a prayer book, a diary and a book about St. Theresa, but, the pope joked, "Certainly not the keys to the atomic bomb!"
He said he carried his own bags because "It's normal, we have to be normal. We have to be accustomed to being normal."
CNN's Eric Marrapodi and Daniel Burke contributed to this report.
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