Since time began the big question has been asked. If God loves us why do people die? Does a loving God want mankind to suffer and die? Before sin man didn't suffer and die. There was no death. The truth is death is the very way God shows us his love and mercy.
In the book of Genesis God had this to say after man had first sinned:
Genesis 3:22 And the LORD God said, "The man has now become like one of us, knowing good and evil. He must not be allowed to reach out his hand and take also from the tree of life and eat, and live forever."
Why was it so important that Adam must not be allowed to eat from the tree of life and live forever? Does God not want Man to live forever? We know that's not true at all. A very well known verse, a verse even non-believers usually know by heart says otherwise.
John 3:16"For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life.
So why was it so important that man must not be allowed to eat this fruit that would cause him to live forever? Was it to punish man? Maybe partially, but not completely. There are other very important reasons! The first reason is that if man could not die then Jesus could not have died on the cross. God is not only a God of love but of justice. If Christ could not have died to take the penalty for the sins of man then man would have lived eternally in a state of sin that could never be justly penalized. This is something a just God could never allow. The second reason is that God does want us to live forever, but God does not want us depending on a piece of fruit to give us eternal life. Rather than have us live eternally in sin apart from Him, He wants us to live eternally in a relationship with Him and to depend on Him for our eternal life. What a truely lowley state we'd be in. Imagine the world as it is today with all it's problems. Now imagine it could never end. No one would ever die. Men like Hitler and Nero would still be alive today. Sure they would not be murderous, but still just as evil.
Instead God has allowed death to enter in to the world. And one day, those who enter in to eternal life by His plan will live in a world where there is once again no death. And it will be a world free of sin and evil.
So it was because of His grace and mercy God allowed death to exist, not in spite of it. And if you repent of your sins and ask Jesus to be your Lord and savior you will have eternal life HIS way.