As you likely know, metanoia is the word translated as "repentance" in the Bible. The root concept of the word means "to turn," associated with a "change" or "turn" of heart and mind. For Peterson, metanoia is a sign of humble fallibility--a willingness to admit error, to learn, to grow. That's a really healthy posture when life hits you with some hard truths, especially truths about your own failings and limitations. Here's Peterson:
The devil, traditional representation of evil, refuses recognition of imperfection, refuses to admit "I was in error, in my action, in my representation"; accepts as a consequence of unbending pride, eternal misery--refuses metanoia, confession and reconciliation...
Such refusal--the inability to say, "I was wrong, I am sorry, I should change," means the death of hope, existence in the abyss...
The act of metanoia is adaptation itself: admission of error, founded on faith in ability to tolerate such admission and its consequences...
As a Christian, I don't have much to add to this passage. It really speaks for itself, and profoundly so. I'll just add a personal reflection.
Jana and I have been married for almost 31 years. And in all those years, the times when I've tipped most toward the devil are those times when I've closed myself off from admitting and saying out loud and with a full heart, "I was wrong, I am sorry, I should change." A diabolical pride stood in the way, blocking relational healing. It’s so, so hard to get to "I was wrong, I am sorry, I should change," but if you refuse the relationship is doomed and hell is created on earth.