Neither necessary nor sufficient.
One needn't look to the blood war for examples of individuals who, though they fight evil are not good themselves. History is replete with examples of this and literature has even more. In Phil Foglio's webcomic Girl Genius, for instance, Baron Von Wolfenbach fights evil quite effectively, but it would be difficult to classify him as good.
Similarly, I don't believe that it is necessary to fight evil in order to be good. In the D&D cosmology, for instance, the newest lantern archon may never fire a light ray in anger or take any other step to fight evil, but he is still good. That said, I think that when the right circumstances arise, a good person would fight evil, and, it he (or she) backed down from the fight, he would not be good anymore (or perhaps would reveal that he was never really good in the first place). Fighting evil is not a necessary condition for being good, however, because those circumstances are not universal.