The first human woman, eve, saw the fruit very attractive when the snake told her that it has got special powers. Her husband, Mr. Adam, had specifically told her about the tree, the commandment he received from God himself, not to eat from it!
One day she was alone. Mr. Adam had gone for work. Mrs. Adam, Eve, decided to break God’s commandment, not to eat the fruit of that particular tree. It was Devil who influenced her to eat from the tree speaking through a snake.
When God came to know about their action, he expelled them from the Garden of Eden. That put an abrupt end to their prospect of everlasting life on earth. See how that single action, to disobey God, pushed the whole of humankind into untold miseries for the generations to come!
Read the rest of the story from the Bible.