Why the crucifixion?

I have been reading GK Chesterton. He advocates trying to see Christianity fresh as if you were someone who had never heard it before. I would be very confused if I did so.
The passion of the Christ is the central theme of Christianity. According to Christians this is the central act of the world and central to the message of Christianity. Some questions I would have. Q represents my fresh view. A my understanding.

Why did Christ need to die?
A: To save us from death.
B: But, God gave us life before. Why does he need to die to give us life again?
A: Because he is going to give us a better type of life: eternal life. In giving us that God takes something that is finite and makes it infinite. To balance that celestial checkbook something finite

A: To save us from sin, of which we are all guilty.
Q: What can God do about our guilt?
A: God can forgive us; we are then cleansed from sin.
Q: How can God be the one whose forgiveness we need if we hurt somebody else?
A: I don’t know. It just works. I know from my experience as well as others. Perhaps God can do this while we can’t because we are his, he made us.

Q: What is sin, and why do we need to be saved?
A: Sin is living contrary to the purposes for which God created us: namely to be happy together (unity) [this is why God is three]. Sin therefore is anything that separates us from God and with our fellow being. Separation refers not just to location but also desires, hopes etc. God as our creator knows these things better than we do. Ultimately it is only through his authority that we can hope to be more unified.
Q: Why does God need to be involved? Can’t I just change what I am doing?
A: No. You broke the order which makes it possible for people to live together. As an outlaw you are an enemy. How can they know you aren’t just lying in order to take advantage of them again? A trusted third party has to accept liability for you so you can be re-integrated into society. [this is another reason why god is three]

Q: Why didn’t Christs life create paradise here, why is this world still fallen? Also, why didn’t he do this sooner?
A: It was His plan from the beginning that we live in a fallen world, where because of imperfections we can have real choice. His kingdom is not of this world. Ultimately the choice is to reign in our own solitary hell, or be subjects in his kingdom.

To a certain extent I think that this is a true story that God is telling the world (as a character in it) so we can understand love.