God knew He had to punish them, because they had disobeyed Him. So, He sent them out of the garden where they were loved and protected to a world where there was evil and death present. God was terribly hurt, but loved Adam and Eve very much. He knew He had to do something so they and their offspring wouldn't be lost forever. So He made a plan with Jesus Who would come to earth one day as a man.
Scripture References:
Genesis 3:14-15
