Gen. 3:22 Then the LORD God said, "The people have become as we are, knowing everything, both good and evil. What if they eat the fruit of the tree of life? Then they will live forever."
There is mercy with the Lord. God had explicitly forbidden Adam and Eve from eating of the true of good and evil. When they listened to Satan and ate of the fruit of the tree, they broke their covenant relationship with God. They were now sinners and would bear the consequences of their sin.
God had also planted the tree of life in the Garden. If man were to eat of the fruit of that tree, he would live forever. Because God loved man, He spared him from living forever under the curse of their sin. He banished man from the Garden and put angels around it to prevent man from returning to it. He lovingly protected man from an eternal life of sin.
God also provided man with a way to get rid of his sin. God does not want anyone to die in their sin so He sent Jesus to come and be our Savior. The soul of man is eternal spirit. Everyone will live on after they die. When we accept Jesus as our Savior and live for Him, we live on in heaven with Him. If we reject Jesus and die in our sin, we live on without Him in eternal hellfire.
Wherever we end up spending eternity, it will be by choice. God dignifies man by letting man choose where he will spend eternity. He has made himself known to us and we will be judged on the basis of our knowledge of Him. Our lives are a reflection of our choice. We can either live for the pleasures of earth or the pleasures of heaven. Choose carefully whom you will serve. If you make the wrong choice, you will have eternity to think about it.