How does Elie lose his sense of self through his suffering and despair in Night?

In the book Night Elie had always had
a very spiritual side that he thought would help him through life.  He and his family
are taken off, separated, and he and his father are forced to endure the hardships of
the concentration camps.

Elie slowly loses his self
identity.  Initially, he has lost the boy he had been.  He then begins to lose his
spirituality when he witnesses the young boy being hung.  Later as he finds himself
repulsed that his father is drawing attention to himself by his inability to keep up
with work and becomes sick, Elie loses who he was as a son.