Radical change has become the new norm in Rome under the first six months of the pontificate of Pope Francis. The first Pope from the Americas has brought with him – “from the ends of the earth”, as he put it – a fundamentally new perspective. Now conservatives in the Vatican are braced for what could be, next week, a bigger change than anything so far.

A new council of eight cardinal advisers – mavericks to a man – will meet for the first time on Tuesday to offer guidance from outside the dysfunctional and self-serving Vatican bureaucracy known as the Roman Curia. The new Pope from Argentina has tasked them with the massive job of reforming the Curia. The new body has been described by the leading ecclesiastical historian Professor Alberto Melloni, of the University of Modena, as the “most important step in the history of the church for the past 10 centuries”. Even allowing for a little Italian exaggeration, this is clearly a big deal.

Pope Francis caused a stir from the outset by eschewing the monarchical trappings of the papacy and presenting himself as an icon of assertive humility. But there has been much more to him than a Pope who rejects the papal palace, eats at the refectory table in his hostel, carries his own bags and makes impromptu calls on his mobile to a variety of ordinary people in response to letters whose envelopes were address only to “Pope Francis, The Vatican, Rome”.

He has also been radical in his pronouncements on Church teaching. On the plane back to Rome from World Youth Day in Brazil – where his final Mass had attracted three million worshippers – Francis spoke freely in answer to reporters’ questions on a wide range of topics. His softening of Rome’s attitudes to gay people – “Who am I to judge?” – grabbed the headlines. But in 80 minutes of Q&As the new Pope signalled change in many areas.

That was a message reinforced this month when he gave a 12,000-word interview to a Jesuit publication. It sent shock waves through the Catholic Church.

He criticised it for putting dogma before love, and doctrine before serving the poor. It had grown “obsessed” with abortion, gay marriage and contraception and become a church of “small-minded rules”. Where his predecessor, Benedict XVI, wanted a smaller, purer church, Francis wanted an inclusive one which was a “home for all”.

“We have to find a new balance,” Pope Francis concluded, “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.”

Conservative Catholics have struggled with all this, stuttering that the new Pope was changing no doctrine but merely offering a different style. Many of his comments could have been made by Pope Benedict, they said – it was only Francis’s tone that was different.

Liberal Catholics, by contrast, who had felt out in the cold during the 35 years during which John Paul II and Benedict XVI occupied the papacy, were optimistic that there would be substance to match the style.

But it is now becoming clear that the new Pope is bent on real change. To some extent, style and substance have been interwoven. When Francis visited the southern Italian island of Lampedusa in July – to show solidarity with the African refugees whose flimsy boats find it the easiest part of Europe for them to reach – he ruffled feathers in the Vatican. First, he did not consult the Vatican equivalent of the prime minister’s office, the Secretariat of State. And he tried to book his own flight on Alitalia, until the airline’s people rumbled him.

Symbol and substance have gone hand in hand elsewhere. At the scandal-hit Vatican Bank he first told all the cardinals on its supervisory board that they must forgo their €25,000 annual stipend. But then he set up a five-person commission of outsiders, including a Harvard law professor, to investigate the bank which has been accused of money laundering. In a handwritten document he gave them powers to summon any documents and data they deemed necessary and told them to report directly to him.

He has made moves to rehabilitate liberation theology – the Latin American movement which said the Church should work for the political and economic, as well as the spiritual, liberation of the poor. The theology was condemned as Marxist by the Vatican under previous popes, and its advocates were silenced. But Pope Francis last month met the father of liberation theology, Gustavo Gutierrez, in Rome. He has asked one of the previously silenced theologians, Leonardo Boff, to send him his writings. And he has removed the block on the canonisation of Archbishop Oscar Romero, the champion of the poor in El Salvador who was martyred under a right-wing military government.

Most recently, he has upset traditionalists in Rome by announcing that he will stop granting elite priests the honorary title of “monsignor” with its anachronistic aristocratic resonance – it means “my lord”.

The big question is: will the new Pope be able to institutionalise that and the rest of his raft of changes so that they cannot be reversed by a conservative successor? There are two keys to that: the appointments he makes and the mechanisms he must establish to lock in reform.

The trend in his appointments has been steadily away from the conservatism of the previous three decades. He has replaced Benedict XVI’s Secretary of State, Cardinal Tarcisio Bertone, whose chief qualification for the job appeared to be that he was a friend and theological soulmate of the previous Pope. Bertone departed with bitterness, lashing out against the “crows and vipers” who had undermined him.

In his stead Francis has placed Archbishop Pietro Parolin, a talented and respected Vatican diplomat, who will rebuild the Holy See’s international credibility and be a key player in Curia reform. In the previous era he fell foul of Bertone and was shunted off to be Papal Nuncio in Venezuela to get him out of the way.

His return was just the start of what looks to be a big round of far-reaching changes. The old guard, who were reconfirmed in their previous jobs only “provisionally” when Francis took over, are being steadily removed. New men are in place in the key Vatican departments.

The extent of the change they are expected to usher in was evident from Francis’s big interview this month. Asked allusive religious questions the Pope plunged in with direct answers. Quizzed about “Ignatian spirituality”, Francis responded with comments on reform. “Many think that changes can take place in a short time,” he said, warning that it would take time to “lay the foundations for real, effective change.”

He spoke openly about his failings as a younger man when – confirming for the first time the revelations made in my book Pope Francis – Untying the Knots – that as leader of Argentina’s Jesuits, aged just 36, his “authoritarian and quick manner of making decisions led me to have serious problems”. He brought up the thorny issue of infallibility and insisted it applied to judgements arrived at by the whole church, including the ordinary people, not just the Pope.

Asked whether the Church should drop its rule that divorced and remarried people should not take communion, he said that pastoral care came before dogma, and brought up homosexuality in the same context. Not all the dogmatic and moral teachings of the Church were equivalent, he declared.

God is to be encountered in the world of today, he said. The Christian who “wants everything clear and safe… will find nothing”. Tradition and memory of the past must help us to have the courage to open up new areas to God. The church was wrong in the past in accepting slavery and the death penalty. “Ecclesiastical rules and precepts that were once effective… have now lost value or meaning.” The church must “grow in its understanding” and “mature in its judgement”.

For a Pope this is explosive stuff. The task facing him now is to translate that vision into practice. That is the business that will begin on Tuesday at his first meeting with his Group of Eight cardinal advisors.

They will arrive in Rome well prepared. The eight men come from every continent and corner of the Church. All have been noted critics of the Vatican in the past. In their home provinces they have been consulting local bishops and lay experts about the priorities for reform. They have been in email and telephone discussions with one another. Each has been assembling ideas of his own on how to make Rome more accountable to local churches, so that the Curia is their servant and not their master.

The challenge for Pope Francis next week will be to begin the task of synthesising and coordinating the approaches of his new advisers. He has said he wants to proceed carefully, and with the collegial consensus of his brother bishops. But, at the age of 76, he knows he does not have that long.

On Thursday he will celebrate the feast of St Francis of Assisi – whose name this first Jesuit Pope took. In his mind will echo the words that his namesake reputedly heard issuing from a crucifix in the 12th century: “Francis, repair my Church for it is in ruins.”. The new Pope knows he is charged with no less a task.

‘Pope Francis – Untying the Knots’ by Paul Vallely was published last month by Bloomsbury