what physical and emotional qualities do you think eliezer possessed to make him a surivor?

I think that, although it was tested and broken down, Elie's faith kept him going for much of the novel. Elie also wanted to help his old father as much as he could. I also think, to a certain extent, Elie had to turn himself off. Elie had to live from moment to moment, insulating himself from the Hell that he was plunged into.