What is the meaning of the tree of good and evil?

A:Genesis 2:17 says that God forbade Adam to eat from the tree of the knowledge of good and evil. In chapter 3, we find the serpent, which modern Christians assume to be Satan, tempted Eve to eat the fruit of the tree. In one form or another, the story of the tree of knowledge appears in other ancient religions of the Middle East. The tree was guarded by the serpent in Sumerian legend, as shown by iconic images that appeared on Sumerian seals.