I mean to write more on this, and probably at Pyro. But I thought I'd throw out this brief thought for the weekend.
I've heard a lot of my fellow-Reformeds rail against explaining "repentance" as "a change of mind."
Not me. It is a change of mind. That's exactly the significance of the Greek word μετάνοια (metanoia).
What I think the critics of this explanation should do is say, not "It does not mean a change of mind," but "It does not mean a merely superficial adjustment of opinion." What they say, and what they criticize, are two different things.
Let's say you smoke cigarettes. I ask you what you think about it on Monday. You say, "I see nothing wrong with it." Then I ask you on Friday, and you say, "I've changed my mind. It's a loathsome and destructive habit, and I must stop immediately."
Then I check back two weeks later, and you're still smoking like a factory, without a single attempt to stop.
My conclusion: you adjusted your opinion superficially, but you didn't really change your mind about smoking. Because a real change of mind issues in a change of behavior, however imperfectly and however gradually.
The mind is the wellspring of life (Proverbs 4:23). It is how we are renewed (Romans 12:1-2).
Perhaps a better explanation would be: repentance is a fundamental change of mind from ungodly beliefs to God-honoring beliefs, which issues in appropriate fruits of attitude and behavior.