[the Jew] Who smiles to see how full his bags are crammed, Which money was not got without my means. (Prologue 31-32)
This isn't quite as good as seeing baby pictures, but it does tell us something about what Barabas was like before we meet him. Two things to notice: (1) Machiavel is indicating that Barabas wasn't above deceit beforehand, and (2) it sounds as though his deceit is intrinsically tied up with his love of money. Hey, Marlowe, the 13th century called: it wants its stereotypes back.
Daughter, I have it. Thou perceiv'st the plight Wherein these Christians have oppressed me. Be ruled by me, for in extremity We ought make bar of no policy. (1.2.267-70)
This is right after Ferneze has confiscated Barabas's property, which Barabas has claimed is an act of "policy," or political scheming. He's telling Abigail that, given that they're "in extremity," they have to fight fire with fire, and employ their own "policy," i.e. trickery, to help themselves. And you know what? So far, we're kind of agreeing with him.
We Jews can fawn like spaniels when we please, And when we grin we bite; yet are our looks As innocent and harmless as a lamb's. (2.3.20-22)
If you can't beat them, you might as well live up to their expectations. This is one of the many places where Barabas's bad personality seems to be because he's Jewish rather than because he's, you know, a murderous psychopath. And we think he's totally playing it up.
Thus every villain ambles after wealth, Although he ne'er be richer than in hope (3.4.53-4)
Translation: LOL, Ithamore. Barabas says this right after he's promised Ithamore to fully embrace him as his heir. So, just when we think that Barabas and Ithamore are totally evil BFFs, Barabas reveals that he's using Ithamore in the same way he uses everyone else.
Now I have such a plot for both their lives As never Jew nor Christian knew the like! (4.1.115-6)
Barabas doesn't just lie, cheat and steal—he really gets a kick out of it. And something else: here's he's not just saying that he's just can't help being evil because he's Jewish. He's actually so evil that even Jews can't imagine how evil he can be.
And, thus far, roundly goes the business. Thus, loving neither, will I live with both, Making a profit of my policy, And he from whom my most advantage comes Shall be my friend. (5.2.111-15)
Friendship on Malta: not unlike Snakes and Ladders. Barabas doesn't really like anybody, but he also isn't going to turn up his nose at making nice with somebody who can help him. Even his right-hand-man, Ithamore, is simply a tool he leverages for "advancement."
Why, is not this A kingly kind of trade, to purchase towns By treachery and sell 'em by deceit? Now tell me, worldlings, underneath the sun If greater falsehood ever has been done?(5.5.46-50)
Who's the boss? Barabas! Well, for a few minutes, anyway. This comes late in the play, by which point the stakes have been upped from Barabas sneaking a bag of gold out of his house to gaining control of all of Malta. Even here, though, Barabas isn't as interested in actually ruling Malta as he is in the awesomeness of his plot.
Leave nothing loose, all leveled to my mind. Why, now I see that you have art indeed. (5. 5.3-4)
Barabas is ordering his carpenters to build the mechanism he's going to use to murder Calymath. This is kind of cool because we get to see Barabas's plot in real life. Instead of just quietly plotting and playing people off of each other, he's escalated to "leveling the world to his mind." He's not just fitting the plots to his environment; he's changing the environment to fit his plots. (In other words: he's totally terraforming Mars.)
Barabas: […} Say, will not this be brave?
Ferneze: Oh, excellent! Here, hold thee, Barabas. I trust thy word, take what I promised thee.
[Ferneze offers Barabas the money again]
Barabas: No, Governor, I'll satisfy thee first… (5.5.41-44)
Ferneze trusts Barabas about as far as he can throw him (not far), but he knows there's no one better when you need to build a nefarious death-trap. Barabas has the market on nefarious death-traps cornered. Pro tip to Ferneze: if Barabas is refusing money, though, you'd better watch out.
Know, Governor, 'twas I that slew thy son; I framed the challenge that did make them meet. Know, Calymath, I aimed thy overthrow, And, had I but escaped this stratagem, I would have brought confusion on you all… (5.5.81-85)
In classic villain form, Barabas spends half of his death speech making sure that Ferneze and Calymath know about his plots. For a guy who's spent the majority of this play lying (and definitely to these two), why is it so important to him to confess?Actually, would you even term this a "confession'?Would you take your last moments to tell everyone "Guess how evil I am?On second thought, never mind.Let metell you how evil I am.REAL EVIL, folks"?