Although the Maltese Christians—particularly Ferneze and the two priests—present themselves as agents of morality, Marlowe makes it clear that these men are frauds and hypocrites. This complicates Barabas's role within the play, for it challenges his status as the obvious villain. There is no clear struggle between good and evil, although the Maltese demonize Barabas. Instead, the major characters are presented as strategists who maneuver themselves into positions of strength or weakness depending on their ability to deceive. Even the Catholic priests turn their backs on religious morals when it suits them, shown in their attempts to outmaneuver each other to win Barabas's money.
This is an overarching theme that ties in with many others within the play, particularly religious hypocrisy. Essentially, the characters display an ability to strategize that is alien to ideals of religious sincerity. As Machevill asserts in the Prologue, "religion [is] but a childish toy." Instead of religion and the power of Divine Providence, many characters place their trust in schemes and strategies. Marlowe treats this subject ambiguously. Although the Prologue satirizes Machiavellian scheming, the rest of the play suggests that statesmen must manipulate to protect their own interests. For example, Ferneze is only able to survive and free Malta by outmaneuvering Barabas. In turn, Barabas avoids capture for a long period of time through anticipating other people's moves and motives. Marlowe ultimately leaves us wondering whether or not he believes in Machiavellian tactics. The play's heavily ironic tone could support the view that man is driven by his own motives. Alternatively, it might suggest that our ability to control events always comes second to God's will—which would make political scheming redundant.
This theme dominates the play as it grows to consume Barabas. Notions of vengeance obsess the protagonist, and what Barabas qualifies as a personal injury becomes increasingly broad as the play progresses. Barabas turns from specific wrongs done him by individuals—such as Ferneze—to focus on wrongs done him by Christian society and the world in general. Even those characters who have been loyal to Barabas, or who have brought him great advantages, come under fire. Calymath is a notable example, for the protagonist repays the Turk's generosity with treachery. Barabas even threatens Ithamore at a point when the slave is most loyal to his master, saying, "I'll pay thee with a vengeance, Ithamore." The protagonist's all-consuming wrath has a momentum unlike anything else within the play, including the motivations of the other characters. As a theme, vengeance contributes to the stagy feel and self- referential theatricality of The Jew of Malta.