Italian Cardinal Carlo Maria Martini has described the Roman Catholic Church as being "200 years behind" the times.
The cardinal died on Friday, aged 85.
Italian newspaper Corriere della Sera has published his last interview, recorded in August, in which he said: "The Church is tired... our prayer rooms are empty."
Martini, once tipped as a future pope, urged the Church to recognise its errors and to embark on a radical path of change, beginning with the Pope.
Thousands of people have been filing past his coffin at Milan's cathedral, where he was archbishop for more than 20 years.
The cardinal, who had retired from the post in 2002, suffering from Parkinson's Disease, is to be buried on Monday.
Martini, a popular figure with liberal stances on many issues, commanded great respect from both Pope John Paul II and his successor Pope Benedict XVI.
The cardinal - a member of the Jesuit religious order - was often critical in his writings and comments on Church teaching, says the BBC's David Willey in Rome.
He was a courageous and outspoken figure during the years he headed Europe's largest Catholic diocese, our correspondent says.
In his last interview, given to a fellow Jesuit priest less than a month ago and published the day after his death, the cardinal made sweeping criticisms of the Catholic Church.
Catholics lacked confidence in the Church, he said. "Our culture has grown old, our churches are big and empty and the church bureaucracy rises up, our religious rites and the vestments we wear are pompous."
Unless the Church adopted a more generous attitude towards divorced persons, it will lose the allegiance of future generations, the cardinal added. The question, he said, is not whether divorced couples can receive holy communion, but how the Church can help complex family situations.
And the advice he leaves behind to conquer the tiredness of the Church was a "radical transformation, beginning with the Pope and his bishops".
"The child sex scandals oblige us to undertake a journey of transformation," Cardinal Martini says, referring to the child sex abuse that has rocked the Catholic Church in the past few years.
He was not afraid, our correspondent adds, to speak his mind on matters that the Vatican sometimes considered taboo, including the use of condoms to fight Aids and the role of women in the Church.
In 2008, for example, he criticised the Church's prohibition of birth control, saying the stance had likely driven many faithful away, and publicly stated in 2006 that condoms could "in some situations, be a lesser evil".