Why?

The question is why did Jesus have to die? I'm not looking for the normal "To save us." Answer. Why was his dying necessary for us to get to heaven? Why is it that "The wages of sin is death" (Romans 6:23)? Why is the punishment of Adam and Eve eating of the fruit from "the tree of the knowledge of good and evil." (Gen 2:17) Doesn't that imply that God made it so that Jesus would have to die to save us. Why would he do that? Why set up that kind of pain? To show us how bad sin is? Just by disobeying God, Adam caused Jesus to have to die. But then, God set it up that way. I just wonder why. Sin separates us from God. There has to be a way to get back to Him. We can't work it off, because there will always be sin. Why did God have the tree there? Why did Adam let Eve eat the fruit? As I just learned by reading the Wild at Heart book, Adam was right there. The serpent was talking to Eve but Adam could've stepped in and stopped it. I'm not making a coherent point, I know. I'm kind of throwing all this out there. "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." (Gen 3:21) Also, why is that tree there? Where are these trees today? Why didn't God want us to live forever? Don't we live forever in heaven anyway (once we are saved that is)?