Achebe rejects the Western notion of art for its own sake in essays he has published. Instead, Achebe embraces the conception of art at the heart of African oral traditions and values when he writes that "Art is, and always was, at the service of man.... Our ancestors created their myths and told their stories with a human purpose; any good story, any good novel, should have a message, should have a purpose." How, then, would you interpret the human purpose of Things Fall Apart?
Through Achebe's characterization of Okonkwo, he has rendered a vision of human struggles. His vision is one in which there is ultimate purpose. The issues that Okonkwo wrestles with are ones in which there are clear implications for all human beings. An example of this would be Okonkwo's feeling that he has been abandoned by his deity. Okonkwo feels a profound disconnect between he and his personal god. This helps to illuminate Achebe's belief that a basic human struggle is one in which individuals seek to reconcile their relationship with the divine. This is a statement of human purpose in Achebe's work, one in which the reader has to wrestle with their own sense of being in seeing Okonkwo's.
Another example of this idea that Achebe's work speaks to a larger purpose in being would be in the issue of social alienation that Okonkwo experiences. This is a condition in which Okonkwo wrestles with how "things fall apart" socially and personally. The grieving for what has passed is a part of this. The pain intrinsic to a condition of isolation is something that Achebe constructs as part of what it means to be human. The examination of the individual as part of their own community as well as their own connection to self is an integral part of understanding Okonkwo. In rendering this vision, it becomes something reflective that the reader is able to understand in their own sense of being in the world.