What are the marks of a super-naturally changed heart?

This is one of the questions the apostle Paul address as he writes to the church in Corinth. He takes aim at the blessings of self-forgetfulness in 1st Corinthians 3:21-4:7. He’s after a deep-rooted, life-altering change on the inside, that brings about much greater joy than some superficial outward tinkering will (as our best self-help efforts can only hope for).

In an age were people-pleasing, puffing up your ego, and building your resume are seen as the methods to ‘make it,’ the apostle Paul calls us to find true rest in God, through blessed self-forgetfulness.

“The more we get to understand the Gospel, the more we want to change. Friends, wouldn’t you want to be a person who does not need honor — nor is afraid of it? Someone who does not lost for recognition — nor, on the other hand, is frightened to death of it? Don’t you want to be the kind of person who, when they see themselves in a mirror or reflected in a shop window, does not cringe either? Wouldn’t you like to be the type of person who, in their imaginary life, does not sit around fantasizing about hitting self-esteem home-runs, daydreaming about successes that gives them the edge over others? Or perhaps you tend to beat yourself up and to be tormented by regrets. Wouldn’t you like to be free from them? …
You will probably say that you do not know anybody like that. But that is the possibility for you and me if we keep on going where Paul is going [in 1 Corinthians 3:21-4:7]. I can start to enjoy things that are not about me…
This is gospel-humility, blessed self-forgetfulness. Not thinking more of myself as in modern cultures, or less of myself as in traditional cultures. Simply thinking of myself less.”
—Tim Keller, The Freedom of Self-Forgetfulness: The Path to True Christian Joy, pp. 34-36.