Pope Francis has repeated his criticism of people who "idolise" wealth and turn things into gods.

The pontiff, celebrating Mass at his Santa Marta residence, where he chose to live over the grandeur of the traditional papal apartments, said people should look beyond the beauty of things and the temptations of the here and now towards the transcendent.

"This idolatry of being attached to the beauty of the here and now, without a sense of the transcendence, we all run the risk of having that. It's the idolatry of immanence. We believe that these things are almost gods and they will last forever. We forget about that fading away."

He was speaking as well-informed Rome observers warned that his reforms are starting to "bite".

Caroline Wyatt of the BBC says that although Pope Francis has called often for a "poor Church" that serves the poor, his problem, is that the Church is not poor.

Referring to new revelations of greed and mismanagement in two new books based on leaked documents, Avarice by Emanuele Fittipaldi and Merchants in the Temple by Gianluigi Nuzzi, she reports fears that these leaks are part of a "dirty tricks" campaign against a Pope who is determined to ensure that the Church hierarchy practises what it preaches.

She says the books make abundantly clear the scale of the challenge that faced by those tasked with cleaning up the Vatican.

Pope Francis told a meeting of bishops in Florence this week: "May God protect the Italian church from every pretence of power, image and money." During his time in Florence, the Pope chose to eat lunch with the poor, lining up at a Caritas soup kitchen to eat with a plastic spoon.