In his cramped hut at the end of an alleyway in the coastal Tanzanian town of Bagamoyo, traditional healer Dr Msilo treats patients with a variety of mental and physical problems.
To locals, he is known as a witch doctor, and his treatments involve casting out evil spirits, as well as administering traditional potions.
People are keen to seek out his services, regardless of their religious affiliation.
"God provides medicine for all people - Muslims, Christians and pagans," he says.
"They all know that the trees were given by God, and He gave some people the power to heal."
The continuing devotion of many Africans to elements of traditional belief is well known.
But Dr Msilo is just one example of a key trend identified in a major new study of African faith.
The Pew Forum interviewed more than 25,000 people in 19 sub-Saharan countries about all aspects of faith and belief.
The results show that the overwhelming majority of Africans in those countries are committed followers of either Islam or Christianity.
But alongside regular visits to church or mosque, they will also visit traditional healers like Dr Msilo, who offer a connection with the ancient beliefs that pre-date Christianity and Islam in Africa.
The survey underlines that in most countries, Christians and Muslims live peacefully side by side.
Fewer than one third of respondents felt religious conflict was a problem in their country - though 58% said it was in Rwanda and Nigeria, where there have recently been clashes between rival communities around Jos.
Where tensions grounded in religious difference do exist, there is a strong correlation with ethnic divisions - as was the case in Jos. Christians are more likely to regard Muslims as violent than vice-versa.
On average, more than 40% of Christian respondents associated violence with Muslims, whereas 20% of Muslims associated violence with Christians. A key concern identified was the lack of understanding that both Muslims and Christians have of each other.
At a recently established Muslim-only school in Bagamoyo, teachers were struggling to obtain adequate resources. They compared their facilities with those of Christian schools that attract funding from foreign missionary organisations.
Deputy headmaster Abdala Maropia said that in spite of this inequality, there were generally no tensions between Christians and Muslims in the town.
"Here in Tanzania honestly we don't mind whether one is Muslim or Christian - we live in peace and harmony," he says.
But other teachers admitted they knew very little about Christian beliefs, and they acknowledged this can lead to misunderstanding.It is clear that religion is a defining part of most people's life.
At the fish market, a Muslim woman explained that of course she attends prayers five times each day.
She seemed to find it strange that she was even being asked about the significance of religion.
The Pew Forum study found that 93% of people in Tanzania said religion was a very important part of their life.
Both Muslims and Christians would like to see their own religion exerting legal influence within their country.
Some 63% of Muslims favour the implementation of Sharia law, and just over half believe the Caliphate (the unification of the Islamic world under a single ruler) will be re-established during their lifetime.
One of the most consistent Christian responses across all 19 countries concerns the return of Jesus Christ to earth, with 61% believing it will happen in their lifetime. But there is also significant concern about the impact of secular influences - particularly Western media.
While most believers admit to enjoying Western film, music and television, there is real concern about its impact on morality. In Tanzania, 80% of respondents believe that morality has been undermined by such entertainment.
Getting a wholly consistent picture from such a wide-ranging piece of research is unlikely. But the Pew Forum's study underlines the substantial influence of both Christianity and Islam in the countries surveyed.
As sub-Saharan Africa looks to the future, an intriguing attachment remains to the traditional beliefs that many Christian and Muslim leaders condemn.
Though it may be that influences from beyond Africa, not least those available through the power of the internet, may yet contribute most to changes in the religious landscape in future.
AFRICA MOST RELIGIOUS PART OF WORLD
Researchers say they've found the most religious place on Earth -- between the southern border of the Sahara Desert and the tip of South Africa.
Religion is "very important" to more than three-quarters of the population in 17 of 19 sub-Saharan nations, according to the survey.
In contrast, in the United States, the world's most religious industrialized nation, 57 percent of people say religion is very important.
"On a continent-wide basis, sub-Saharan Africa comes out as the most religious place on Earth," said Luis Lugo, director of the Pew Forum on Religion and Public Life, which released the study last week.
According to the survey, 98 percent of respondents in Senegal say religion is very important, followed by 93 percent in Mali. The lowest percentage was reported in Botswana, 69 percent, which is still a healthy majority.
"That begins to paint a picture of how religious sub-Saharan Africans are," Lugo said.
The study is part of the Pew-Templeton Global Religious Futures Project. More than 25,000 sub-Saharan Africans responded in face-to-face interviews in more than 60 languages.
While the study confirms that Africans are, indeed, morally conservative and religiously pious, researchers explored a variety of topics, including religious tolerance, polygamy, the role of women in society, and political and economic satisfaction.
Islam and Christianity dominate as the most popular religions in the region -- a stark reversal from a century ago when Muslims and Christians were outnumbered by followers of traditional indigenous religions.
But for the past 100 years, indigenous spirituality has been diluted as missionaries carried Islam and Christianity throughout the African continent.
The study reports that the number of Christians in sub-Saharan Africa grew faster than the number of Muslims, from 7 million in 1900 to 470 million in 2010. One in five of the world's Christians lives in sub-Saharan Africa.
While a majority of African Muslims are from the northern region of the continent, nearly 234 million live below the Sahara Desert.
Indigenous African beliefs have not disappeared, but are often incorporated into Islam and Christianity, the report found. A number of sub-Saharan Africans believe in witchcraft, evil spirits, reincarnation and other elements of African spirituality. More than half of the people surveyed in Tanzania, Mali, Senegal and South Africa believe that sacrifices to ancestors or spirits can protect them from harm.
Mary Dhavale, a native of Tanzania who now lives in Atlanta, describes herself as a "righteous child of Jehovah God" and drives two hours every Sunday to worship at a Pentecostal church. She also said her grandfather was a traditional healer.
"You may call him a witch doctor, but he did good things for the people," Dhavale said.
Dhavale's grandfather attended Catholic services for most of his life, even as he concocted herbal drinks and crafted charms to ward off evil spirits or expose petty crimes in the neighbourhood.
"If your child is sick or if your car is spoiled, people would go to my grandfather and find out who did it," Dhavale said. Such syncretism of religions is not uncommon in Africa.
Sulayman Nyang, a professor at Howard University's African Studies Department, said by honouring traditional religious practices, sub-Saharan Africans are able to maintain their African identity and strengthen ethnic unity.
However, Nyang said indigenous religions are not practised in a pure form because Africans want to maintain their "dignity" and "want to be accepted into the new world of modernity."
According to the Pew survey, most sub-Saharan African Muslims are Sunni. Within Christianity, Catholicism dominates in Guinea Bissau, Rwanda and Cameroon, while Liberia, South Africa, Zambia, Kenya, Nigeria, and Botswana are predominantly Protestant.
Pentecostalism is rapidly spreading and deeply influential across the region, and also across Christian denominations.
"Casting out of the devil or evil spirits, high degree of apocalyptic expectations, the health-and-wealth `prosperity gospel' is the new Christian phenomenon of the Pentecostalism in sub-Saharan Africa," Lugo said.
The study suggests that the degree of concern about religious conflict is often interwoven with concerns about ethnic conflict. In Rwanda, for example, tensions between Hutu and Tutsi ethnic communities erupted in the 1994 genocide. Nigeria continues to be wracked by Muslim-Christian violence.
The 19 countries represented in the survey comprise 75 percent of the population of sub-Saharan Africa. The countries are: Botswana, Cameroon, Chad, Djibouti, Democratic Republic of Congo, Ethiopia, Ghana, Guinea Bissau, Kenya, Liberia, Mali, Mozambique, Nigeria, Rwanda, South Africa, Senegal, Tanzania, Uganda and Zambia.