The issue of Christianity relates to this novel because of the way in which Christianity is shown as the manifestation of colonialism that slowly enters this Ibo tribe and destroys it. It becomes evident as the missionaries spend longer in this tribe that the arrival of Christianity amongst the Ibo is accompanied by a splitting in the tribe as some (at first the outcasts) are attracted to Christianity and some are not. This is an issue that is raised by the elder at the end of Chapter 19 who raises the presence of Christianity as being something of a thorn in the foot of the tribe, that if untreated could kill it:
"An abominable religion has settled among you. A man can now leave his father and his brothers. He can curse the gods of his fathers and ancestors, like a hunter's dog that suddenly goes mad and turns on his master. I fear for you; I fear for the clan."
The issue of Christianity, therefore is the cause of the tribe and of Okonkwo falling apart. Just as the insidious presence of Christianity in the tribe causes division and the eventual destruction of the weaker culture, so to does the conversion of Nwoye to this "foreign religion" cause Okonkwo to fall apart.