Just a little more than a century ago, most Africans (76%) practiced traditional African religions. According to historical estimates from the World Religion Database, in 1900, just 14% of the people living in sub-Saharan Africa practiced Christianity; even fewer were Muslim (9%). Today, however, Africa is overwhelmingly populated by followers of these two religions. The number of Christians has grown 70-fold, and now a majority of sub-Saharan Africans are Christian (57%). The Muslim population has grown 20-fold, and now nearly three in 10 sub-Saharan Africans (29%) are Muslim. Just 13% are followers of traditional African religions. Sub-Saharan Africa now is home to about one in five of all Christians in the world (21%) and more than one in seven of the world's Muslims (15%).
Source: Pew Research Center