One quote that is particularly important comes when Liesel first meets Hans, her adoptive father. Her description of his face, and in particular his eyes, is particularly important to establishing what kind of character he is and also foreshadows later events that show his goodness:
Liesel observed the strangeness of her foster father's eyes. They were made of kindness, and silver... Upon seeing those eyes, understood that Hans Hubermann was worth a lot.
The metaphor of silver is used here to convey value, and its combination with kindness is something that quickly establishes Hans as a good character who determines to go on being good, whatever the cost, even during one of the bleakest chapters of humanity's history. This goodness is of course something that Liesel herself experiences, as she arrives at her adoptive family a very troubled young girl, tormented by what she has already experienced.
Hans later goes on to show that love very practically by revealing the truth to Liesel about her mother and the real reason why they are separated. Note what he says to Liesel about the letters he wrote to her, thinking to send them to Liesel as if they were from her mother:
You know, Liesel? I nearly wrote you a reply and signed your mother's name... But I couldn't. I couldn't bring myself.
It was love that caused Hans to write those letters in the first place, but it was a deeper and more genuine love that causes him to tell her the truth about her mother and allows her to identity the cause of her unhappiness, which is of course Hiter.