Vatican City - Pope Benedict XVI said in his first encyclical Wednesday that the Roman Catholic Church has a duty through its charitable work to influence political leaders to ease suffering and promote justice.
The document, "God is Love," also warns against sex without unconditional love, which he said risked turning men and women into merchandise.
It had been eagerly anticipated because inaugural encyclicals offer clues about a pontiff's major concerns. The 71-page document can be seen as an effort by Benedict to stress the fundamental tenet of the Christian faith - love - and assert the church's duty to exercise love through its works of charity in an unjust world.
In the encyclical, Benedict rejected the criticism of charity found in Marxist thought, which holds that charity is merely an excuse by the rich to keep the poor in their place when the rich should be working for a more just society.
That appeared to be an extension of the pope's firm rejection of the Marxist-inspired liberation theology, which he firmly denounced in his early years as the Vatican's chief doctrinal watchdog.
Liberation theology, which originated in Latin America, holds that criticizing the oppression of the poor and marginalized should be central to Christian theology, and that the Christian faith should be reinterpreted specifically to deliver oppressed people from injustice.
Benedict conceded that Marxist models of dealing with injustice by trying to provide for social needs did help the poor. But he said Marxism was a failed experiment because it could not respond to every human need.
"There will always be suffering which cries out for consolation and help. There will always be loneliness. There will always be situations of material need where help in the form of concrete love of neighbor is indispensable," he said.
Benedict stressed that the state alone is responsible for creating a just society, not the church. But he said the church has the right and the duty to be involved in politics by helping "form consciences in political life and stimulate greater insight into the authentic requirements of justice as well as greater readiness to act accordingly, even when this might involve conflict with situations of personal interest."
Benedict said the church's work caring for widows, the sick and orphans are as much a part of its mission as celebrating the sacraments and spreading the Gospels. However, he stressed the church's charity workers must never use their work to proselytize or push a particular political ideology.
"Love is free; it is not practiced as a way of achieving other ends," he wrote.