One problem we see, as lawyers, is that clients come to us and present a biased fact statement, with every argument favoring their side. However, we know from experience that no case is so one-sided. There is always a weakness in your case, or "another side to the story" that paints both parties in a bad light - but maybe one moreso than the other.
And the same could be said of Republicans, who propose what are often preposterous ideas in the name of "protecting the peepul."
Or take religions. Is the new Pope good or evil? He certainly thinks he is helping the world, but while he has made a lot of liberal-sounding noises, when push comes to shove, well, it turns out he goes back to the conservative ways of all the prior Pontiffs. He doesn't see himself as evil, but if you support birth control or gay rights, you may think of him as thus.
Maturity is being able to see the other fellow's side to the story, even if you think it is wrong. And in lawyering, as in any battle, you have to be able to see the other fellow's side if you expect to anticipate his every move. The worst mistake you can make is to assume the other side knows they are wrong, and will capitulate readily once you point out the error of their ways.
Yes, there is evil in the world. Sadly, the people practicing it don't see themselves as evil.