How does pearl Buck satirize Western Christian missionaries in the novel?

Revolutionary propaganda circulates among the poor men of the city. Wang Lung, who cannot read, takes the flyers nonetheless so that O-lan can use them as stuffing for their shoes. The Americans distribute some flyers as well that feature images of Jesus -- first depicted as Western, then later as Chinese. Wang Lung hears a young man speak of rising up against exploitation of the poor. Wang Lung thinks that this talk does not explain everything, for though he knows that the rich control money he knows that they cannot control the weather, which affects his money as much as the rich do.