Pope Francis on Thursday called on the world to reject the "idolatry of money", claiming that greed was driving societies to ruin.
In an interview in his modest apartment in the Vatican, the pope told the glossy French magazine Paris Match that the world economic system as it stands was "unsustainable".
"Capitalism and profit are not diabolical if we don't turn them into idols. They are not if we just leave them as tools," he said.
"Nevertheless, if money and profit at any price become the idols that we adore, and if greed is the basis of our social and economic system, then our societies are heading towards ruin."
The comments to a magazine whose usual fare is the lives of celebrities, billionaires and royals, hammered home the Argentinian pontiff's twin concerns about the need to tackle poverty and the environment.
"Man and all creation must not be at the service of money... humanity must renounce its adoration of money and instead put at its centre the person, the common good and future generations who will people the Earth after us," he said, saying a world climate change conference in Paris in December could help turn that around.
Christians, he said, were realists and not inclined to preach catastrophe. "However, we cannot hide the obvious. The world (economic) system is unsustainable."
On the wars in Syria and Iraq, the pope said the world had to act in the "face of the emergency", but said it also had to deal with the causes of the conflicts.
"Let's ask ourselves why there is so much war and violence... Let's not forget the hypocrisy of world powers who talk about peace but sell arms under the table."