An open letter from Pope Emeritus Benedict that blames the Catholic Church's sexual abuse crisis on homosexuality and the sexual revolution of the 1960s is drawing deep criticism from Catholic theologians in the U.S. who call it divisive and "embarrassingly wrong."

"Among the freedoms that the Revolution of 1968 sought to fight for was this all-out sexual freedom, one which no longer conceded any norms," Benedict writes in a lengthy treatise released Wednesday in his native Germany. "Pedophilia was then also diagnosed as allowed and appropriate."

James Bretzke, a theology professor at Marquette University, calls the pedophilia claim puzzling, saying pedophilia has never been accepted by "anyone anywhere close to the cultural mainstream."

"A casual or uninformed reader of Benedict’s text might conclude that this position was widely held by “liberal” theologians," Bretzke told USA TODAY. "Nothing could be further from the truth."

Benedict says expanded access to pornography helped fuel the crisis. At about the same time period, Catholic moral theology suffered a collapse that left the church ill-equipped to combat the trend, he added.

"In various seminaries, homosexual cliques were established, which acted more or less openly and significantly changed the climate in the seminaries," writes Benedict, who ceded his reign to Pope Francis six years ago.

The former pope says a series of cover-ups exacerbated the crisis, and that the Vatican was ill-equipped to press for criminal trials for so many cases.

"Why did pedophilia reach such proportions?" Benedict writes. "Ultimately the reason is the absence of God."

Benedict says he was inspired to speak out by a February gathering of leaders of the world’s bishops’ conferences at the Vatican to discuss the crisis. He said he wanted to contribute to "a new beginning" sought by Francis.

Hundreds of priests, bishops and others in the church have been accused of sexual abuse dating back for decades. Pope Francis, at the February gathering, cited the "scourge" of sexual abuse and said it was the responsibility of church leaders to "confront this evil afflicting the Church and humanity."

Benedict pledged at his surprise 2013 resignation to remain “hidden from the world” and not get involved in church issues. The Vatican had no immediate comment on the letter, but it didn't sit well with many Catholics.

John Thavis, a former Catholic News Service reporter and author of "The Vatican Diaries," said Benedict's letter was neither accurate nor helpful.

"It illustrates why Benedict's initial decision to retire to a life of silence was a prudent one," Thavis told USA TODAY. "When a retired pope issues statements on these kinds of issues, it undercuts the efforts of the current pope."

Andrew Chesnut, chair in Catholic Studies at Virginia Commonwealth University, said the letter can only serve to further divide the church's liberals and conservatives at a time when Francis has been calling for unity.

"It's a myopic and reductionist critique that erroneously assumes systemic sexual abuse perpetrated by clergy didn't exist prior to the 1960s," Chesnut said. "It also ignores the fact that the sexual revolution of the 1960s was largely a Western European and American phenomenon when even by the late 1960s, the majority of Catholics were in the Global South, especially Africa and Latin America, where systemic abuse is even more acute due to less oversight."

Brian Flanagan, associate professor of theology at Marymount University, called the letter "embarrassing."

"The idea that ecclesial abuse of children was a result of the 1960s, a supposed collapse of moral theology, and 'conciliarity' is an embarrassingly wrong explanation for the systemic abuse of children and its cover-up," he said.

David Gibson, director of Fordham University's Center on Religion and Culture and a Catholic convert, described Benedict's opus as "deeply problematic and damaging at a crucial time" when the church is trying to heal.

Gibson, on Twitter, said that contrary to Benedict's claims, many abusers are outwardly devout and conservative, and that abuse has occurred "forever" and in very devout regions, not just the more secular West.

"Benedict's path is not supported by facts, and he is not the Pope," Gibson tweeted. "Just acting like one. Those are problems."