The cardinal's comments came days after the conclusion of the 2014 extraordinary synod on the family, which debated making it easier for divorced and civilly remarried Catholics to receive Communion.

"We will be counterproductive if we have anger or hate in our hearts, if we lapse into sterile polemics against a surprisingly small number of Catholic opponents," the cardinal wrote.

Cardinal Pell's remarks came in a homily he had prepared for a celebration of Mass in the extraordinary form Oct. 24 at Rome's Church of the Most Holy Trinity of the Pilgrims.

The cardinal was unable to celebrate the liturgy, part of the Populus Summorum Pontificum pilgrimage to Rome for devotees of the traditional Latin Mass, on account of bronchitis. In an additional prepared text, he assured those present that his sickness was the only reason he was unable to attend.

In the cardinal's absence, his personal secretary Father Mark Withoos celebrated the Mass and read the homily.

The "college of bishops and all synods work by consensus," Cardinal Pell wrote. Before next October, Catholics have to work to build a consensus "out of the present divisions," he wrote.

"Pastoral practice and teachings can only be change by consensus," he wrote.

"Doctrine does develop, we understand truth more deeply, but there are no doctrinal back-flips in Catholic history," the cardinal wrote. "The apostolic tradition announced first by Christ and founded in the Scriptures is the touchstone for truth and genuine pastoral practice."

"We, and especially you young people, must live this in love, giving reason for your hope," he wrote. "This is a unique opportunity, which we must seize in God's name."

Cardinal Pell also wrote about the importance of the papacy in defending and developing doctrine.

"The role of the successor of St. Peter has always been vital to Christian and Catholic life, especially as the touchstone of doctrinal fidelity and as a resolver of disputes, pastoral as well as doctrinal," the cardinal wrote.

"The church is not built on the rock of Peter's faith," he wrote, "but on Peter himself, despite his faults and failings."

"Pope Francis is the 266th pope and history has seen 37 false or antipopes," he wrote.

"The story of the popes is stranger than fiction," the cardinal wrote, and today "we have one of the more unusual popes in history, enjoying almost unprecedented popularity. He is doing a marvelous job backing the financial reforms," he wrote

Cardinal Pell concluded his written remarks with a prayer "I was taught as a child: May the Lord preserve the Holy Father, Pope Francis, and give him life. Keep him safe on earth and deliver him not up into the hands of his enemies."