From Isaiah 1:16-17 (NKJ):

16 “Wash yourselves, make yourselves clean;
Put away the evil of your doings from before My eyes.
Cease to do evil,
17 Learn to do good;
Seek justice,
Rebuke the oppressor;
Defend the fatherless,
Plead for the widow.”

This scripture provides a very interesting contrast between good and evil. It describes good as something that we have to learn to do against a naturally evil behavior. Good is something that we must fight for, not just outwardly at the injustices in the world, but inwardly, within ourselves. We must wage war within our very being. It is only then that good can prevail in our lives by the grace and power of Christ.