Paul's description of Scripture's purpose maps onto the leadership task: teaching (what's right), rebuking (what's wrong), correcting (how to get back on track), and training (the capacity to stay there). Great leaders do all four.
Many leaders are comfortable with teaching and training but avoid rebuking and correcting. The result is a team that is never pushed to grow. This is not kindness — it's abdication.
Matthew 18:15 gives a relational framework for correction: go directly, go privately, go with the goal of restoration. Not to humiliate. Not to prove a point.
People who are developed become loyal. People who feel stagnant leave, or worse, stay disengaged.