One of the central themes in The Jew of Malta is the distinction between authenticity and appearance. For instance, Ferneze argues that by confiscating all of Barabas' wealth, he is not at fault but is merely enacting the curse of the Jews' ancestral sin (Matthew 27:25). Nonetheless, Ferneze exploits religion to suit his own purposes. He ignores the Christian doctrine of kindness to all and shows no mercy towards the Jews. When he requires money, the Jews are treated as outsiders, despite clear evidence that the governor has previously depended on their financial backing. Ferneze is not the only character displaying duplicity. The friars, who appear to be pious, are actually motivated by a desire for Barabas' fortune. However, Barabas is the master of deceit, pretending to be outraged and impoverished by the governor's confiscation of his assets, while remaining composed, aware of his hidden riches. Barabas also tricks both Lodowick and Mathias, making each believe Abigail will be with them, while secretly orchestrating their demise. He deceives the friars about his conversion, setting them against one another, and even misleads the Turks into thinking he is their ally, while plotting their assassination. Barabas is adept at deception, yet fundamentally, he is not much different from the other characters—just more inclined to kill rather than simply steal from his victims.

The play's deepest betrayal unfolds between a father and his daughter. Abigail is so devoted to her father that she agrees to deceive the nuns to recover his hidden fortune. Yet, Barabas betrays her by plotting to kill the man she loves. Mathias, who has done nothing to harm Barabas, is merely a pawn as both Lodowick’s friend and Abigail’s suitor. Barabas considers Mathias disposable because he is a Christian and, therefore, worthless in his eyes. By murdering Mathias, Barabas shatters the implicit trust that a father would never intentionally hurt his daughter. As Abigail lies dying, her thoughts are consumed with saving her father. She confesses his murders to a friar—not to harm him, since the priest is bound by his vows to keep the secret—but in an effort to protect him. She remains unaware of her father's betrayal, as he has intentionally poisoned her. Other betrayals occur, such as Ithamore's disloyalty to his master driven by his lust for Bellamira, but none are as profound as Barabas' betrayal of his daughter's love.

In The Jew of Malta, greed is a driving force for nearly every character. Barabas, who already has considerable wealth, could have easily given half of his estate to the governor and still been left with a significant amount. Yet, he is determined to keep everything and even acquire more. Similarly, Ferneze is eager for more wealth. Instead of making sacrifices to pay the tribute to the Turks, he chooses to extract the money from the Jewish community, demanding all of Barabas' fortune rather than just half. Calymath's father waited ten years before requesting the tribute, not because he forgot, but because he believed that letting the debt grow would make it impossible for the citizens of Malta to pay, allowing him to seize everything. Ithamore, who is promised half of Barabas' estate as his heir, becomes impatient and continually increases his blackmail demands for more money. Pilia-Borza and Bellamira are also motivated by greed; they first attempt to steal from Barabas and then resort to blackmail to get his wealth. Even the friars are more interested in material gain than spiritual pursuits when they try to convert Barabas. The relentless pursuit of wealth has affected almost everyone in Malta.

Marlowe's Elizabethan...