The Tree of the Knowledge of Good and Evil is an idea from the Bible. It was a special tree in a garden, and God told Adam and Eve, who were the first man and woman, to not eat the fruit from this tree. God said that if they did, they would be punished. For disobeying, Adam and Eve were then banished from the garden and it was never allowed to be visited again.
This story is about understanding what it means to make choices, and understanding the difference between good and bad. Eating the fruit from the tree was a bad choice, and God said that it would lead to punishment. This means that it is important to know what choices will lead to good things, and what will lead to bad things. When we make a good choice, that is called being good. We should always try to make good and wise choices.