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 for ever.’
God was willing to allow us to live forever right up until the point where we sinned!
Because of that sin we are not allowed to live forever; at least not until we are no longer guilty…
Jesus paid for the debt we owe for the sins we do, making it possible for us to join God back in Heaven eventually!