There are different ways that parents praise their children when they are being really good. One compliment parents often give their child is: "you are such an angel."
We use this form of praise because in our minds we have an image of angels as perfect holy beings that never do anything wrong. However, while it is true that angels are very special beings, calling someone an angel is not such a compliment.
We are taught that despite the fact that angels are holy and pure they are stationary beings. They never grow, never improve and never change. Each angel is created with a specific spiritual mission, which it constantly maintains without ever improving or failing. There are angels that serve God with love and those that serve Him with awe. Whatever spiritual personality they are given is the one they will always have, without making it better or worse.
People are not angels. We are not always perfect. We make mistakes, do what we shouldn't and sometimes fail in our mission. But the unpredictability and inconsistency of our personality is also our strength. It means that we never have to stay the same. Just like we can fail, we can also change and improve. Just as we can do that we shouldn't, we can also do more good that we originally expected. We are the only beings that are not limited by our natural instincts or personality. Our potential for growth, improvement and change is endless.
Don't expect your children or others to be angels. We should hope for them to be real humans - people who sometimes make mistakes, but who can always bounce back and become stronger than ever before.
Don't be an angel - just be a good decent human being.