Essays / The Kite Runner: A Marxist Perspective [4]

Hi everyone!
I need to write a culminating essay for my grade 12 university English class.
It is to be about analyzing one theme of the kite runner using the Marxist literary theory.
I was thinking about looking at the theme of friendship in the novel, or possible coming of age.
I know that I will be dealing with class relations, societal divisions, social restraints, etc...
But I need some help coming up with a thesis- I don't know where to begin!
Can anyone please help? :)