Pope Benedict XVI celebrated mass at a stadium hosting tens of thousands on Sunday in Benin, wrapping up a visit that saw him sign off on a grand vision for his church's future in Africa.

Some 50,000 people filled the stadium in Cotonou, the economic capital of Benin, a country considered both the heartland of voodoo and a bastion of Catholicism -- and where the two religions often mix.

Benedict arrived at the stadium in his popemobile amid a joyous welcome from the faithful, many wearing skirts or wraps with his picture. The 84-year-old pope received warm cheers when he took a baby in his arms.

Before his arrival, the crowd applauded each time the sun appeared from behind the clouds, some crying out, "Jesus!"

Benedict, also projected on giant screens outside the stadium, told the crowd that what Christ "asks of us is to follow him along the way, to serve, to be attentive to the cry of the poor, the weak, the outcast."

"Today, so much still binds us to the world of the past, so many fears hold us prisoners and prevent us from living in freedom and happiness. Let us allow Christ to free us from the world of the past," he said.

The mass capped off a three-day visit by the pontiff to the West African nation, his second trip to the continent, before his departure on Sunday afternoon.

On Saturday, he signed off on a roadmap for the Roman Catholic Church in Africa at a basilica in the city of Ouidah, a centre of voodoo, with the Temple of Pythons and its 30-odd snakes just across the street.

The document signed by Benedict -- an apostolic exhortation called "The Pledge for Africa" containing conclusions from a 2009 synod of African bishops -- includes peace, reconciliation and justice as its main message.

It calls for good governance, the abolition of the death penalty and denounces abuses, particularly against women and children, while describing AIDS as a mainly ethical problem that requires a medical response.

Changes in behaviour are needed to combat the disease, including sexual abstinence and rejection of promiscuity, it adds.

The Catholic Church's position on AIDS and the use of condoms has long been controversial and carefully scrutinised, particularly in sub-Saharan Africa, home to nearly 70 percent of the world's HIV cases.

The pontiff's visit to the country has been heavy in symbolism, in a region that served as a major slave-trading centre and coming 150 years after what is considered the evangelisation of Benin by missionaries.

Slaves departing from Ouidah and elsewhere took their traditional voodoo beliefs with them and transplanted them in the Americas.

Benedict's visit also occurred with the Church facing a major challenge from evangelical movements that have made huge gains on the continent, attracting hundreds of thousands of followers.

At the same time, Africa also has the world's fastest-growing number of Catholics.

In a speech on Saturday, Benedict denounced corruption, warning it could lead to violent upheaval, and called on African leaders not to rob citizens of hope.

"At this time, there are too many scandals and injustices, too much corruption and greed, too many errors and lies, too much violence which leads to misery and to death," he said at Benin's presidential palace.

"These ills certainly afflict your continent, but they also afflict the rest of the world. Every people wishes to understand the political and economic choices which are made in its name. They perceive manipulation and their revenge is sometimes violent."