Answer:
The major missionary activities from Europe and North America came late in the 19th century, during the Scramble for Africa.
Early colonizers carried with them the belief that native needed to be saved from their own backwards religion and way of life. Some, in order to do this without generating much hostility introduced missionaries, who came in as friendly good-news-bearers in order to gain the trust of the natives.
Christian evangelists were intimately involved in the colonial process in southern Africa. The missionaries discovered increasingly that the medical and educational services they could provide were highly welcome to Africans who were not responsive to theological appeals. When Christian missionaries came to Africa, some native peoples were very hostile and did not accept the missionaries in Africa. Even though there were some Christian missionaries that went about colonizing the native Africans in unchristian ways, some missionaries were truly devoted to colonizing through peaceful means and truly thought that the people of Africa needed to be taught the Christian gospel.
David Livingstone (1813–1873), a Scottish missionary, he worked after 1840 north of the Orange River with the London Missionary Society, as an explorer, missionary and writer. He became one of the most popular British heroes of the late 19th-century Victorian era. He had a mythical status that operated on a number of interconnected levels: Protestant missionary martyr, inspirational story of rising from the poor, scientific investigator and explorer, imperial reformer, anti-slavery crusader, and advocate of British commercial and colonial expansion. This clearly shows that Christian missionaries were effective tools in the colonization of Africa, they came in posing the image of coming to save the natives and slowly but effectively engulfed them in colonialism.