This idea has great relevance to everything we do. We often find ourselves mired in thoughts that limit our ability to grow. “That’s just the way I am. What can I do? I didn’t choose to be born stubborn, hot-tempered, selfish, and arrogant. Ask my Creator why He made me this way.”
While it is true that each individual was created with a different nature and temperament, and it may well be that one person has a greater tendency toward anger, jealousy, or arrogance than another, the entire focus of our lives is supposed to be on changing our natures.
To do that, however, we must clearly see change as possible, as something within our capacity. For that reason, Hashem gave us the mitzvah of milah – so that we can have a permanent reminder of our ability to change.