Religion

In the Belgian Congo in 1959 Christianity was the main religion. The number of native Congolese priests totaled about 400. The Belgian administration was back then seen as what we call a paternalistic colonialism. The educational system was mainly dominated by the Roman Catholic Church and sometimes by Protestant churches. In 1959 about 99.6% of educational facilities were controlled by Christian missions.
The traditional religious beliefs in a supreme being, the power of the ancestors, spirits of nature, and the efficacy of magic were mostly abandoned when Christianity was introduced. There was a sizable Christian population, including the local section of the Church of Jesus Christ on Earth by the Prophet Simon Kimbangu (Kimbanguism). The rest of the Congos population continues to follow traditional beliefs. The foreign communities included a small Jewish population and some Hindus and Muslims.
The way religion in the Belgian Congo were 50% were Catholic, 20% were Protestant, 10% were Kimbanguist 10% were Muslims and 10% believed in the traditional religious beliefs of their ancestors. Kimbanguism was seen as a threat to the colonial regime and was banned by the Belgians. Kimbanguism now has about three million members. As well as being the largest religion in the country with about 30 million members, the Roman Catholic Church in the Democratic Republic of the Congo is one of the largest Christian Churches in Africa roday.
Islam was first brought to the country by slave traders operating out of East Africa and Zanzibar. Traditional religions embody such concepts as monotheism, animism, vitalism, spirit and ancestor worship, witchcraft, and sorcery and vary among ethnic groups. The syncretic sections often merge Christianity with traditional beliefs and rituals, but may not be accepted by mainstream churches as part of Christianity.

Sources
-https://www.cia.gov/library/publications/the-world-factbook/geos/cg.html
-http://en.wikipedia.org/wiki/Democratic_Republic_of_the_Congo#Religion
-http://www.britannica.com/eb/article-40797/Congo
-http://en.wikipedia.org/wiki/Belgian_Congo
-http://www.adherents.com/adhloc/Wh_365.html