This may work for Adults as well as children, but only when seen modeled by the mentor...
Learning the concept of “Choices & Consequences” as opposed to attaching labels to people allows for growth and maturity, as well as taking responsibilities on our actions.
Emphasizing that no one is neither “Good” or” Bad”, empowers us to feel we are in control of our actions. Knowing that even with good intentions, the results may not always be favorable allows for Grace Forgiveness, and Growth (of others, and of ourselves).
Labeling people as “Good” or “Bad” leads to thinking that we are powerless to change the kind of person we are. The Label “Bad” or “Good” turns into a justification for the actions and choices we make. (We hear this often from guilty people, “I did it because I’m a bad person”. As if they had no other choices but to do what they did because of “Who” they are.)
When we think in terms of “Choices & Consequence”, we allow ourselves to isolate incidents and enable ourselves to deal with each of them accordingly. We begin to realize that it is within our power to choose the action to take. If our action did not produce a favorable result at first, we are able to see it as an opportunity for growth. Something we can do better the next time we come faced with the same situation. This thinking process also helps us to go through life with confidence that even though we make mistakes, we’ll be okay because the next time, we can choose to change the way we handle the situation. We can think ahead as to what we can do differently to produce a positive result next time we are faced up with the same situation. As in any other learned skill, we get good at it by consistent Awareness, Education and Practice. For most incidents, the natural consequence of our actions provides a good guidance as to whether or not the choice we made is positive or negative.
Labeling people as “Bad” can send a message of hopelessness. A reminder from time-to-time that one is born “Bad” or “Good” helps to build self-worth. That even though we make mistake, we are capable of improvement and turning things around.
Affirm your children when they do what is good. Encourage them to respond differently next time. Instead telling them are being a "Bad" kid, gently and lovingly tell them that they chosen to act poorly and tell them why (when we constantly say or do something hurtful to others, that type of action will tend to push people away). This places emphasis on the action as opposed to the person.