No one is locked into his past. The self-image can be redrawn, and the whole striving mechanism swings to serve the new picture the moment the aim itself changes. Turning from the old pattern is not cosmetic; it resets what a person moves toward.
Here the change counts only when it reaches the conduct, keeping the LORD's statutes and doing what is right, not merely wishing. And the promise waits at the end of that turn: he shall surely live. When a man stops rehearsing the old self and starts acting from the new one, the life that follows is a different life.