In part 2, chapter 16 of Chinua Achebe's Things Fall Apart, it's two years later and Obeirika returns to Umbanta and reports that missionaries have built a church in Umufia. They've even converted some villagers to Christianity. The elders are displeased but don't believe the new religion will last. Obeirika has noticed Nwoye among the converts, and he wants to tell Okonkwo of his son's activities. But Okonkwo won't discuss his son, so Obeirika learns from Nwoye's mother how Nwoye became intrigued by the missionaries.
One white man and six converts came to Mbanta. The white man has a commanding presence and speaks through an interpreter. This ends up being comical, because the white man uses the terms, my buttocks, instead of myself. drawing laughter from the crowd. But the white man also claims that the Igbo gods are heathen gods, pieces of wood and stone.
And he goes on to talk about the Holy Trinity, saying there's only one true God. He tells them to turn against their wicked ways and convert. He then promises to bring iron horses to them, though Okonkwo had been hoping for a fight. He walked away from the missionaries, thinking they were crazy. But Nwoye was fascinated.
The hymn they sang seemed to answer a vague and persistent question that haunted his young soul. Something inside Nwoye had broken with the killing of Ikemafuna. The new religion provides a relief within his parched soul. Christianity also offers Nwoye a way to break from his father.
Okonkwo is mentioned in this chapter, but he plays no active role in it. The purpose of the chapter is to document Nwoye's fascination with the missionaries and his conversion to Christianity. His attitudes and beliefs have driven him apart from Okonkwo. After joining the missionaries, when Nwoye is asked about his father, he replies, I don't know.
He is not my father. Readers see that Nwoye and Obeirika share some similarities. Both question the way their society functions. Obeirika, having a better understanding of the young man than Okonkwo does, encourages his friend to be patient with Nwoye.
But as the novel has repeatedly shown, Okonkwo has no patience. The missionaries have spread just as the locust did. The first man was a harbinger, like the first swarm of locusts. However, the missionaries can't be killed off and are slowly infiltrating the clan.