Daniel has devoted his young life to getting revenge on the Romans who killed his father and uncle. He lives in the hills with Rosh, a bandit leader, but Daniel is still young and somewhat naive. He believes that every non-Roman should be allied with them, and every Roman is their enemy. Rosh, being a pragmatic thief and not really concerned with the rebellion itself, is only using the cause to enrich himself. In Chapter 9, Rosh sends Daniel out to rob an elderly man who is secretly buying property outside Israel.
He made it sound like a privilege that Daniel should have the chance. Daniel agreed with him on principle. Why should one greedy old miser live like a king in Antioch while his fellow jews toiled and starved? [...] the man would go on his way unharmed -- but not until he had made a contribution to his country's freedom. Fair enough, Daniel reasoned. Still, his stomach was uneasy.
(Speare, The Bronze Bow, Google Books)
Rosh uses Daniel's passion for revenge to convince him that theft is justified. Daniel believes so strongly in the cause that he is willing to force someone else to participate and contribute, regardless of the man's own wishes. Rosh knows that he can always appeal to Daniel's need for revenge, and so he manipulates Daniel to commit acts outside of Daniel's own moral compass. The manipulation of the cause to gain personal benefits is one of the warning signs that Rosh is not a beneficent character.