Repentance and forgiveness are two important themes that pervade the play. Most characters have wronged others or are wronged. Alsonso wrongfully exiled Prospero, the shipwrecked crew plot to kill Prospero and Caliban, Prospero's slave, betrays him. Only the plotting Antonio shows no remorse for the problems he has caused. Almost every one of these characters repents and begs for forgiveness. The play shows the necessity of repentance when you have committed a mistake.
An interesting topic for a paper is class conflict in "The Tempest." A number of relationships reflect and comment on this theme: Prospero and Alonso, Prospero and his servants Caliban and Ariel, and several other minor relationships such as the Boatswain and the royal party. The conflict between classes is responsible for much of the action that takes place in the play.
It is possible to read the play in a post-colonial context and the relationship between Prospero and Ariel or Caliban as one of master and slave. Prospero is a sympathetic protagonist, but he treats Caliban and Ariel cruelly. The relationship between Caliban and Prospero is especially relevant for a discussion of slavery as Caliban seeks to betray and murder Prospero for his imprisonment. Prospero can even be viewed as a kind of colonialist who arrives on the island and "civilizes" the natives. However, these relationships are all more complex. For example, Caliban's actions can also be read in the context of his relationship to his mother, the witch Sycorax.
At the heart of "The Tempest" is the relationship between Prospero and his daughter Miranda. Prospero has raised his daughter alone after the death of his wife. Miranda's knowledge of humanity comes entirely from her father and his treatment of her stands in contrast to his treatment of the island's inhabitants. Similarly, Ferdinand's loyalty to his father the king shows Ferdinand as an honorable person and a good match for Miranda. These relationships provide insight into the individual characters and perhaps an image of a positive power structure in contrast to differences in class.