Inspired by the question Is a moral society more open to the gospel than an immoral one?.
Are people, by nature, good? Or are people evil by nature?
To define these in terms of the world (as opposed to this being rephrased version of "Are people born into sin?"), a "good" person would be someone who does good things for others, considers others above themselves (or at least is considerate of other people's feelings), and generally wants to do things to benefit or help others.
Evil, by comparison would be people who are egoistical, to the point of being willing to do harm to others for their own benefit. This covers a range of "evil" actions (from manipulative people all the way up to murderous people.)
Another way to view this: "good" could be correlated to "love", and "evil" could be correlated to "hate".
I've heard that some humanists believe that people are, by nature, good people. That people, in general, want to help others, support each other's causes, and do things to benefit others over themselves.
What does the Bible say about this? Are there other extra-biblical Christian documents/doctrine to support one way or the other?