Pope Francis has said the Catholic Church is too focused on preaching about abortion, gay people and contraception and needs to become more merciful.
He warned that the Church's moral structure could "fall like a house of cards" unless it changed.
The Pope used the first major interview of his papacy to explain comments he made in July about homosexuality.
He told a Jesuit magazine the Church must show balance and "heal wounds".
The pontiff used the 12,000-word interview with La Civilta Cattolica to set out his priorities as Pope, acknowledge his own shortcomings and open up about his cultural interests.
'Freshness and fragrance'
His vision for relegating the Catholic Church's reliance on rules marks a contrast to the priorities of his predecessors, John Paul II and Benedict XVI, who saw doctrine as the paramount guide for clergy
"The church's pastoral ministry cannot be obsessed with the transmission of a disjointed multitude of doctrines to be imposed insistently," Francis said.
"We have to find a new balance; otherwise even the moral edifice of the church is likely to fall like a house of cards, losing the freshness and fragrance of the Gospel."
Instead, he said, the Catholic Church must work to heal the wounds of its faithful and seek out those who have been excluded or have fallen away.
"It is useless to ask a seriously injured person if he has high cholesterol and about the level of his blood sugars," he said. "You have to heal his wounds. Then we can talk about everything else."
He said the Church had become tied up in "small-minded rules" and risked losing its true purpose.
"The most important thing is the first proclamation: Jesus Christ has saved you. And the ministers of the Church must be ministers of mercy above all.''
His remarks could generate dismay among clergy in the United States who have already expressed disappointment that Francis has not pressed Church teaching on abortion, contraception and homosexuality.
Last week, Bishop Thomas Tobin of Providence, Rhode Island, wrote in his diocesan newspaper that he was "disappointed" Francis hadn't addressed abortion since his papacy began six months ago, according to AP.
'Home of all'
But Francis said: "We cannot insist only on issues related to abortion, gay marriage and the use of contraceptive methods. This is not possible,'' he said.
"The teaching of the Church, for that matter, is clear and I am a son of the Church, but it is not necessary to talk about these issues all the time.''
Francis created headlines two months ago when he spoke about gay priests during an impromptu news conference on a return flight from Brazil. He said it was not up to him to judge about the sexual orientation of clergy as long as they were searching for God and had goodwill.
In his latest interview, Francis said his remarks were in line with Catholic teaching.
"This Church with which we should be thinking is the home of all, not a small chapel that can hold only a small group of selected people. We must not reduce the bosom of the universal Church to a nest protecting our mediocrity,'' he said.
Francis also used the interview to detail his favourite composers, artists, authors and films, which include Mozart, Caravaggio, Dostoevsky and Fellini's La Strada.