Why Do You Fight?

Last night, I finished the Wheel of Time series. 14 books long, each book being 600-1000 pages apiece, and excellent writing throughout. I've been reading it for around ten years, though it was put on hold quite a few times 'cause it was still being written, then the author died, and a new one had to take over.
And then I finished it.

One of my favorite themes from near the end of the series was the question of what the characters were fighting for. The series ended in the Last Battle, in which mankind makes a stand against the forces of the Dark One. Everyone, regardless of gender or employment or nationality, joins in with the battle. But the question is asked multiple times, first to the main character, than to a few of the vast array (some 2000) of minor characters.

Why are you fighting?
-Because I must.
No, that's not good enough. I know what it is to be a soldier, to know that you have to fight regardless. There is a difference between a man who fights for kingdom and a man who fights for money as a mercenary. They both fight the same fight, but one means something. Why do you fight?
(Paraphrased)

That was the conversation between the main character, Rand, who is to face the Dark One himself one-on-one and save the world. This conversation sets him off to rethink things, and to become the ideal one that the world needed.

It's a real question though. Why do we fight? Why do we keep trying to help people in a fallen world when we know it's all going to end up doing nothing in the long run? Why do I keep working on school and learning, and put myself through so much frustration to keep everything in balance?

At one point, the answer was simply "because God told me to." It wasn't a wrong answer, but it wasn't "good enough," as Rand's father makes it clear in those books. My answer, I suppose, is just that if I take the effort to look past myself, I see other people. And if I can do something, anything to help someone else, that is worthwhile. And if I have the opportunity to do so with a higher degree of excellence, then I have the responsibility to do so.

To drive me onward, I still have those images of Ugandan people in terrible pain, of that patient who was having seizures and had to have a catheter put in, but since the hospital had no catheter, they had to use a small feeding tube, and then despite the work put into helping him, he died the evening following when I had been observing him. Several different tests were being run for the myriad of problems he had, and yet to my knowledge, they never even knew what killed him. I could do nothing to help him, and neither could the doctors.

To drive me onward, I also have the image of a close friend of mine here at school who walked away from her faith about a year ago (I think). I remember when she asked me what kept me believing in God, and I told her that it was just how much I needed Him. I referenced academics in particular, since that does tend to be a place in which God plays a large role. She said that she didn't have the same problem, that she tried to do better at school, and then she did better. No God required. So my honest answer did nothing to help her. She isn't turned off from the faith entirely, but she isn't a Christian right now. I'm one of her best friends here, and she mine, and for the first time, I'm actually terrified that someone is going to hell. It becomes more real. Of course, all I can do is what I would have done regardless and be there for her and hang out as usual. So I continue to be honest.