In comments released as leading figures attend the World Economic Forum in the Swiss resort of Davos this week, Dr Rowan Williams said there is "little or nothing" to suggest rising gross domestic product (GDP) eases poverty levels.
He was arguing that an increase in the value of goods and services an economy produces does not necessarily create benefits for the poorest in society.
Writing the foreword to a report by Christian Aid, of which he is a chair, Dr Rowan said: "We have stopped asking what wealth is for.
"Lacking a coherent picture of what a good human life looks like, we have filled the gap with quantified measures that tell us little or nothing about how far flesh-and-blood human beings are flourishing in all aspects of their experience.
"For Christians, in particular, this is a serious failure: we are in danger of not thinking about what is involved in our belief that we are made in God's image, made for creative engagement in the lives of others that will build them up as they build us up. Wealth is instrumental to this, never an end in itself."
Christian Aid's new report warns the world's elite that "obessing about GDP is not the answer to solving poverty", and it also encourages unhealthy debt levels and consumerism in wealthier countries.
An advisor for the charity, Sue Richardson told Premier: "Simply generating more money - either within an economy or even, in many cases, raising the level of income for people - does not actually address poverty in all of its complexities.
"We discovered that despite incomes growing in Ghana for instance, the northern part of the country is poorer than it was when we began working their."
Click here to listen to Sue Richardson speaking with Premier's John Pantry and Rosie Wright:
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