This Fallen Angel

I am an Angel fallen from heaven
Placed on the world's doorstep to let me in
Before I fell
I watched over all humans
I watched their cruel ways
Wondering how they could hate so much
I see wars over weapons
I see weapons kill others just like them
Why do they kill their own species?
If they only realized they are much the same
They only kill themselves
I'm afraid of this cruel world
I'm an Angel to give hope and realization
But I am only one and that is not enough

This is the first poem out of my genre so I hope it is good please give me some advice on how to improve thanks!