In The Bronze Bow, what is Joel prepared to give up for the cause?

After Daniel splits with Rosh and Joel's rescue, Joel's father informs him that he is sending him to a school in Jerusalem to continue his studies. Joel is resistant to this idea, and tells Daniel that he intends to run away and rejoin Rosh. Daniel, knowing that Rosh is no longer acceptable as the leader of the rebellion, argues against Joel's action.

"A new leader will come," he said. "We must go on making ready."

[...]

"But until he comes, Joel, you must go on studying. That's what you are suited for. When the day comes, we're going to need more than farmers and laborers. We'll need the priests and the scribes too, and you can win them over because you understand them."
(Speare, The Bronze Bow, Google Books)

Daniel correctly points out that the need for soldiers will be superceded by the need for educated men. It is not enough to have people willing to die for the cause; after victory, society will not succeed unless there are educated men able to take over the economic and governmental roles filled by the Romans. If everyone ignores their studies, like Joel, they will win but have no way of continuing civilized society afterwards. Daniel urges Joel to go to Jerusalem, and Joel finally understands the point, accepting that his role will come after victory, changing hearts and minds, not fighting and dying for the cause.