The Hebrew word for repentance is shub β to turn around, to change direction. It is a physical metaphor: you were walking one way, and now you turn and walk the other. This is not primarily an emotional experience, though emotion often accompanies it. It is a directional decision. The prodigal son "came to himself" and then got up and went home. Repentance is recognizing where you are and moving.
The New Testament Greek word is metanoia β a change of mind, a transformed perception. Repentance is not shame management. It is not primarily about feeling bad β it is about seeing differently. When Peter denied Jesus three times and then wept bitterly, what broke him was not guilt spiraling but a new clarity about who Jesus was and who he himself had been in that moment. Metanoia is the sudden, accurate seeing that precedes the turning.
First John 1:9 is one of the most important verses in the New Testament for the daily life of a believer: "If we confess our sins, he is faithful and just to forgive us our sins, and to cleanse us from all unrighteousness." He is faithful β his forgiveness is rooted in his character, not your performance. He is just β he can forgive because justice has already been satisfied at the cross. The cleansing described is katharizΕ, to make completely clean. Not partially, not conditionally. Completely.
Commentary is from a charismatic Protestant perspective, drawing on KJV text and public-domain sources including Spurgeon, Andrew Murray, and Matthew Henry.