British-born David Cooney is Ireland's new ambassador to the Vatican. The top-level diplomat is also secretary general of the Department of Foreign Affairs and will reside in Dublin.

Ireland officially closed its embassy to the Holy See, and embassies in a handful of other countries, saying it was a cost-cutting move; however the timing of the announcement last November coincided with increasing criticism from some Irish government officials over the church's handling of clerical sex abuse claims in Ireland.

In a speech to the group, the Pope said today's modern means of communication make it very quick and easy to know what is happening around world -- both good and bad.

Being much more aware of people's material and spiritual suffering should lead to a new call to action "to respond, with justice and solidarity, to anything that threatens humanity, society and the environment," he said.

Armed conflict, famine, pandemics and people flocking to cities have exacerbated both old and new forms of poverty, and the global economic crisis has caused an increasing number of families to face growing financial insecurity, he said.

When poverty and extreme wealth exist side-by-side in society, it gives rise to a sense of injustice, which can spark rebellion, he said.

"It is, therefore, appropriate that nations ensure that social laws do not worsen inequalities," but help people to live decently, he said.

True human development respects human dignity and lets people take control of their lives, he said. Initiatives using micro-credit or "equitable partnerships," for example, "show that it is possible to harmonize economic goals with social needs, democratic governance and respect for nature."

Pope Benedict said the problem of spiritual poverty also must be addressed. He called on nations to guarantee religious liberty and safeguard their cultural and religious heritage.

Religion helps people see others as brothers and sisters in one human family, he said.

When people have lost all reference to God and spiritual values, it makes it very difficult to distinguish between good and evil and to overcome personal interests for the sake of the common good, he said.

A lack of an awareness of God puts young people at risk, too, as they are then more likely to follow superficial or "fashionable" ideals and "turn to artificial paradises which destroy them."

"Addiction, consumerism and materialism do not fill the human heart," he said, adding that "the greatest poverty is the lack of love."

Compassion and listening bring great comfort and make it "possible to be happy even without great material resources," he said.

"Living simply in harmony with what we believe, should remain a possibility, and become ever more possible," the Pope told the ambassadors.