What is Character?
I like writers that make me slow down and THINK. Dallas Willard is one of those writers. He's a philosopher at heart - one who cares about a good definition. Here's his definition of character, from his most important written work (in my opinion): The Renovation of the Heart (NavPress, 2002).
Our character is that internal, overall structure of the self that is revealed by our long-run patterns of behavior and from which our actions more or less automatically arise. It is character that explains why we use credit reports and resumes and letters of reference to make decisions about people. They do not just tell what someone did, but they reveal what kinds of thoughts, feelings, and tendencies of will that person habitually acts from, and therefore how he or she will act in the future.
But character can be changed. And that, of course, is what spiritual formation in Christlikeness is about.
It may be, for example, that in a certain situation I have injured someone by speaking or acting in anger... But in a reflective moment I may also be remorseful and ask myself if I really want to be the kind of person (have the character of one) who does such things. If I do not want that, it will be necessary to change my thoughts and feelings... [which] can result in my becoming the kind of person who just doesn't do that kind of thing anymore.