The word progress is a very interesting word that needs to be explored in terms of colonialism and this novel. Progress is of course the mantra and the creed of colonialism, and was used to justify the actions of white European nations as they invaded and disrupted traditional cultures and structures as occurs in this novel. Progress is therefore something that is the overt excuse behind the behaviour of the white missionaries and the district commissioner. Certainly progress, in the sense of intentionally improving the lives of some Africans, can be seen in the way that Christianity challenged some of the social heirarchy of Okonkwo's tribe. Note how this occurs in the case of the osu, as indicated in the following description of an osu:
He was a person dedicated to a god, a thing set apart – a taboo forever, and his children after him. He could neither marry nor be married by the free-born. He was in fact an outcast, living in a special area of the village, close to the Great Shrine.
This group of people therefore are treated as outcasts by Okonkwo's tribe, and it is only in Christianity that they can be free from this status. The missionaries would argue that this was progress, as they were advancing the standard of living of this group of people and fighting against the so-called "ignorance" of the Africans. However, throughout the novel, this force of progress is pitted against the desire of Okonkwo and his tribe to remain the same and to carry on as they had always done for generations. Progress is what Okonkwo and his tribe therefore want to avoid, but it is clear from the ending of the novel that it is also an unstoppable force that sweeps up Okonkwo's tribe, whether they like it or not.