Barabas stands out because of his differences. The fact that he is rich, Jewish, and secretive alienates him from Christian Maltese society. Initially, Barabas's only motivation is money. Gradually, however, he grows to loathe his Christian enemies and notions of vengeance begin to consume him. The protagonist goes on a killing spree and murders an entire convent of nuns, along with his daughter, his slave, two young men, two priests, a pimp, and a prostitute. It becomes apparent that Barabas kills because of desire and not because of need. Although the narrator suggests in the Prologue that Barabas is a Machiavellian—Machevill states that his "money was not got without my means"mdash;in reality Barabas has little in common with the real political author. He does, however, personify all the traits that an Elizabethan audience would have understood as quintessentially Machiavellian. He is strategic, dishonest, power-hungry (at least in the sense that he desires to have power over his enemies) and irreligious. But as a dramatic amalgamation of all these different evils, Barabas is a slippery protagonist. A profound ambiguity lies at the heart of his character. His introduction as a comic glutton who "smiles to see how full his bags are crammed" has little in common with his later characterization as a vengeance-obsessed psychopath. Barabas is simultaneously a scheming manipulator who feels no pity for his hapless victims and a greedy old man who jealously guards his wealth.
Marlowe's ambiguous characterization is complicated by the fact that Barabas often earns our commiseration, if not our sympathy. In a society of religious hypocrites, the protagonist is refreshingly honest about his own motives. Although he is accused of being a traitor in Act V, scene ii, earlier scenes show that he was never accepted as a citizen of Malta from the start. He is avaricious, jealous, resentful, and controlling, but he also professes great love for his daughter Abigail. The protagonist is deeply embittered by her conversion and by Ithamore's treachery, which leaves him without an heir. Marlowe intends for our reaction to his character to be profoundly uncertain. At the play's end, Barabas declares his own fantastical notions of destroying the world and dies uttering, "I would have brought confusion on you all, / Damned Christians, dogs, and Turkish infidels." Marlowe's treatment of his character is thus deeply ironic, for we never know whether the playwright is taking stereotypes of Jews or Machiavellians seriously. Marlowe's readers must decide whether he is pandering to these stereotypes or undermining them through satire.
Abigail is the only character who displays genuine love, loyalty, and selflessness in the play. Above all, she remains unmotivated by money and appears to have some kind of moral code (although she is willing to dissemble if it will serve her father's ends). Abigail's dedication to Barabas is proved by her vow to remain loyal to him, following her conversion to Christianity.
However, we should be wary of regarding her conversion as a moral climax within the play. Marlowe uses Abigail's conversion to make a heavily ironic point about the corruption of the Catholic clergy—why would anyone seek to join a religion with such flawed affiliates as Bernardine and Jacomo? It even remains doubtful whether Abigail is a true religious convert at all, for she seems to appropriate Christian prejudice rather than Christian virtues. Her comment, "there is no love on earth, / Pity in Jews, nor piety in Turks," suggests that for all her moral worth, Barabas's daughter is as bigoted as the other Maltese. As James R. Siemon notes, Abigail undergoes a final "anagnoresis" or recognition of her own predicament that is a feature of tragic drama. She states "experience, purchased with grief, / Has made me see the difference of things." The "difference" that she refers to is a religious or racial difference. Thus, Marlowe suggests that Abigail converts to Christianity in a bid to reject her heritage, rather than through true religious belief.
However, Abigail is in many ways a romantic heroine whose relative goodness contrasts with the depravity of those around her—Jew and Christian alike. As with his other characters, Marlowe obscures Abigail's morals and motivations in order to complicate our responses to this character.
Ithamore is less a foil for Barabas than a villainous sidekick who tries to emulate his master's cunning. When the two meet, the slave states that he has no "profession." Barabas replies that he will teach him to be ruthless and indeed, many of the play's murders result from the scheming of these two characters. Despite his grisly past spent killing Christians, Ithamore is more naïve than his master. However, both share a delight in killing for its own sake. Ostensibly, the slave murders to win his master's favor and become his heir but, in reality, Ithamore's crimes are without motive. His dalliance with the prostitute Bellamira shows how susceptible Ithamore is to manipulation. He seems particularly credulous when it comes to Bellamira's scheme to bribe Barabas.
Barabas's great enemy. As the governor of Malta, Ferneze is presented as the merchant's moral opponent—he is Christian, law-abiding, and anti- Machiavellian. However, events in the play undermine this dichotomous characterization, suggesting that Ferneze is as morally bankrupt and Machiavellian as Barabas. In reality, the governor schemes and is dishonest about his motives. This is shown by his decision to tax the Maltese Jews in order to pay the tribute and later, when he breaks his alliance with the Turks. Essentially, Ferneze is a religious hypocrite who hides his lust for power behind ideals of Christian morality.