While Roman Catholicism continues to shrink in Europe, in Africa its numbers have tripled over the past 30 years to nearly 150 million. One of the most influential Catholic leaders on the continent is Cardinal Peter Turkson of Ghana, the Archbishop of Cape Coast. He received the red hat from Pope John Paul II in 2003, making him the first cardinal from Ghana.

In the 1980s Pope John Paul II had acknowledged the increasing importance of the African Church by appointing Cardinal Bernadin Gantin of Benin as head of the Congregation of Bishops, and Cardinal Francis Arinze of Nigeria as head of what is now the Pontifical Council for Inter-religious Dialogue.

Both Gantin and Arinze were once considered papabile. At the next conclave, the figure most likely to be proposed as a possible African pope — the first for 1,500 years, since St Gelasius (492-96) — is Cardinal Turkson.

It is easy to see his appeal. He has an international outlook, having studied in Rome and New York; he is a biblical scholar and is fluent in eight languages. In Ghana he has good relations with the Pentecostal and Evangelical churches, and is regarded as a forward thinker. What is more, at 59, age is on his side.

There are about 3 million Catholics in Ghana. All of its 18 bishops are indigenous, as are 95 per cent of its 1,200 priests. However, there is alarm in the Vatican over the exodus of Catholics in developing countries to Pentecostal and evangelical churches. During a visit to London in October, the Cardinal Turkson suggested that the Catholic Church has much to learn from these churches, not least their emphasis on the Bible and personal conversion.

“I think that our traditional way of making people Catholic needs to be reconsidered. The declaration that Jesus is Lord is meant to be an expression of a person's commitment. It's like somebody being offered knowledge of a person and consciously accepting to enter into a relationship with that person and establish personal ties. This is what holds people in these evangelical churches,” he says.

He added that some priests and bishops were products of “notional Christianity” — they had been brought up in a Catholic home, had a Catholic education, and learnt their theology in seminary, but they had never experienced a personal conversion.

“The danger facing the Catholic Church in Africa is that we just feed people with a few notions. Who is God? What is the Trinity? What is a sacrament? These definitions can be learnt by heart and just repeated to anybody who asks questions.

“At the last meeting I attended of the Council for Christian Unity we discussed the threat of Pentecostals in Latin America. I said that we need to celebrate the gifts of the Holy Spirit more: prophecy, healing, intercessionary prayer and all of that. This is one of the things the Pentecostals do.”

When he visits parishes for Confirmation, the Cardinal Turkson makes time to meet the children the night before and conducts an informal catechesis session with them. He adopts a similar approach to seminarians in their diaconate year, inviting them to live with him. “Initially, they were apprehensive, and didn't know why I was inviting them. I have done this for the past ten years. I get to know them and they get to size me up.

“There have been occasions when I have picked up signals from students that have been useful to me later in dealing with them as priests. If I pick up signals that are really serious, I call them in for a chat. I also ask them their spirituality and prayer life. I tell them it's not enough to pray the breviary. They are encouraged to develop a personal prayer life and deepen their spirituality.”

In some parts of Africa vocations to the priesthood are so plentiful that priests are being sent to Europe. For example, the Missionary Society of St Paul, a Nigerian religious order, has priests working in London and Bristol.

“The few local African churches which have sent priests and missionaries to churches in the West have done so not out of a surplus they have. They have done so as an expression of their charity, solidarity, being each other's keeper, and being in communion with other churches,” the Cardinal Turkson says.

Europe is now mission territory, he adds. “Mission was once understood as missionaries from Europe going to Latin America, Africa and Asia. They were considered to be going on the missions. This led to the impression that mission does not take place here in Europe. Mission was equated with civilisation, so to go on the missions was to go and civilise a population.”

In 2009 Pope Benedict XVI will host a second synod for Africa in Rome. Its theme will be “The Church in Africa at the service of reconciliation, justice and peace”. The first synod was held in 1994.

One topic for discussion will be the Church's opposition to using condoms to combat the transmission of HIV. The Cardinal Turkson has indicated that there might well be a case for them to be considered not as a means of preventing life but of preventing death. Unlike some African bishops, however, he has not spoken openly from the pulpit in favour of condom use, prefering to talk about helping people to make their own decision. But this will just be part of a larger debate about issues such as poverty, injustice, corruption, globalisation and Islam.

“At the second synod for Africa we must look at how we are a Church in Africa. Rwanda was supposed to be 99 per cent Catholic. How could it end up with a genocide?

“We need to realise that probably notional Christianity has been too strong. Instead, we need a radical conversion that will make the presence of God real and personal for each one of us.”