One way to see how Chekhov addresses the greed in human nature and its ability to destroy relationships would be in observing Ivan's and Masha's reactions when confronted with the idea that they might have won the lottery money.
In thinking about the money he might have, Ivan displays the greed that Chekhov believes is a part of human nature. When Ivan considers what he might do with the money, he thinks about traveling. When he realizes that he might have to take Masha with him, his greed starts to emerge. He wants to leave her behind, and enjoy the experience without her. Ivan starts to resent her because she would be "sighing over something, complaining that the train made her head ache, that she had spent so much money." Then, Ivan begins to think that his wife should not be entitled to the money because "She knows nothing about money, and so she is stingy. If she won it she would give me a hundred roubles, and put the rest away under lock and key." Selfishness for money also impacts how Ivan sees his relatives. He thinks that they would want to take a share of his winnings. At this thought, Ivan refers to them as "reptiles," describing them as "repulsive and hateful." The coveting of money also impacts Masha. When she begins to daydream about a world of lottery winnings, she displays territoriality over the money. Chekhov writes that such thoughts cause her to see Ivan "with anger and hatred" because "she had her own daydreams, her own plans, her own reflections; she understood perfectly well what her husband's dreams were. She knew who would be the first to try to grab her winnings." Greed has changed the relationship between husband and wife and how they view the world.
In both examples, the lottery winnings inspire greed. This greed transforms people who originally cared for one another into envious and possessive individuals. It is shown to be a part of human nature, something that lies dormant within the psyche that money illuminates.