Pope Benedict XVI begins his first trip to Africa today, heading for a part of the world where the Roman Catholic faith is flourishing but also facing some of its greatest challenges.

Evangelical churches have grown rapidly in Africa over the past decade, some financed by their counterparts in the southern states of the US which have also dispatched dozens of eager, young missionaries to the continent where there are millions of people still to convert.

In muddy fields and football stadiums across Africa thousands of worshippers gather every Sunday – sometimes for the entire day. Music from churches with names like Church of the Universal Apostle and the Divine Holy Spirit blare out from banks of loudspeakers while the faithful sing, dance and chant.

The Roman Catholic Church, which also faces fierce competition from resurgent Islam, has felt the heat. With one of the world’s largest Catholic populations, estimated at 158 million, though, Africa can still pack them in. More than 500,000 are expected to attend Mass in the Angolan capital, Luanda, celebrated by the Pope.

The Vatican’s uncompromising messages on HIV/Aids, the role of priests and nuns in the 1994 Rwandan genocide and its apparent inability to deliver millions from squalor and poverty has, however, dented its image on a continent that saw its fastest growth during the past century.

“The Catholic Church lacks passion. It’s really not a very exciting place,” Jaoa, a worshipper at Luanda’s “Universal Church of the Kingdom of God”, said on Sunday as he held out his arms to the sky and begged God to expel his demons.

The Pope said he hoped that the six-day trip to Cameroon and Angola would bring hope to Africa. He will begin the visit in Yaoundé, the capital of Cameroon, before moving on to Angola, but many will ask why it took him four years to visit a continent his predecessor came to 16 times.

The stakes are high. By 2025 one sixth of the world’s Catholics – about 230 million people – are expected to live in Africa. The world’s largest seminary is in Nigeria, which borders Cameroon. Last month the Vatican reported that the continent was producing priests at a higher rate than any other part of the world, with ordinations rising by 27.6 per cent in 2007.

The Pope will inevitably address political and social issues such as poverty, corruption, HIV/Aids and armed conflict in Africa. He also will meet Muslim representatives and women’s advocacy groups. After his election as Pope, Benedict described Aids as a “a cruel epidemic which not only kills but seriously threatens the economic and social stability of the continent”, but reiterated the Vatican ban on condoms.

He will also tackle aspects of African Catholicism that he finds less acceptable, including the tendency of some African priests not only to ignore Church teachings on priestly celibacy but also to accommodate tribal traditions such as faith healing.

The visit paves the way for a Synod of African bishops in Rome in October with the theme of “reconciliation, justice and peace”. Last month he noted that in Africa “there is not a tired church, as we often find in Europe, but a youthful church, full of the joy of the Holy Spirit”.