One of the major themes of the characters' lives is infidelity. Matthias is accused of fathering illegitimate children, and his second wife has numerous affairs with men who are in and out of wedlock. Little restraint could be said to be exercised by any of the characters in regard to sexual mores. In addition to marital infidelity, Rejment presents immorality occurring in the realms of business and social relationships among the characters.

The idea of want is central to the novel. As the characters are impoverished peasants, they are in desperate want of many things, but their desires and wants prove too strong. Not only do the characters want to have a good harvest and provide for themselves, but some of them want to amass land. Matthias tries to increase his share of land by marrying Yagna and conducting trade deals. All of the peasants share an overall want because they live in poverty, but some characters' desires extend beyond basic needs.

The idea of blessings occurs throughout The Peasants. The book ends with a beggar blessing Nastka's house for giving him food, and throughout the novel, various things are blessed, such as when Matthias receives Yagna's father's blessing for their marriage. It seems that, left on their own, the blessed things remain good, but when characters are overtaken by greed and lust, they lose control of the things they have been blessed with. Matthias was blessed with Yagna, but he married her in greed and lustful ambition. In the end, she slept with other men and likely fathered an illegitimate child. His own son was banished, and they fought, nearly destroying the town—even though the union had been "blessed." Readers are left hoping the final blessing in the story, that bestowed by the beggar on Nastka's house, will remain pure.