In this great novel, the extent to which the missionary movement can be held responsible for the destruction of indigenous societies and a loss of tribal culture that can only be said to have harmed the people that the missionaries were supposedly coming to help. The white man's coming to the tribe indicates the demise of the Ibo culture and way of life. In the battle for supremacy, the white man's tactic is to rubbish their tribal ways and to show the white man's ways as being better, more civilised and modernised.
Note how the missionaries try to win more converts:
Mr. Brown begged and argued and prophesied. He said that th eleaders of the land in teh futrue would be men and women who had learnt to read and write. If Umuofia failed to send her children to the school, strangers would come from other places to rule them.
Thus fear and manipulation is a weapon of the white man in order to increase the numbers of people going to the schol. The initial converts that the white man gains causes a deep division in the tribe that runs through family lines, as is indicated by the way that Nwoye converts to Christianity against the wishes of his father. As a result of this, death eventually is the only fate of the Ibo culture.