Through Lázaro's constant struggle to survive and climb the social ladder, the novel explores the rigid class system of Renaissance Spain. His experiences reveal how poverty forces individuals to compromise their morals, while simultaneously exposing the fraudulent nature of social respectability and the hollow pretensions of the upper classes.

The parade of corrupt religious figures who serve as Lázaro's masters - from the blind beggar to the priest and the pardoner - presents a scathing critique of institutional religion. Each character demonstrates the gap between public piety and private vice, revealing how religious authority often serves as a mask for greed and exploitation.

Lázaro's journey from innocent child to cunning survivor illustrates how deception becomes a necessary tool for education and advancement in a corrupt society. Each encounter with his various masters teaches him valuable lessons about human nature and the art of survival, though at the cost of his moral innocence.