In the book Uncle Tom's Cabin why does Eva say to Tom, “I would die for them, Tom, if I could”?

Eva wants Tom to know how much she cares for the slaves.She wants to be like Jesus and die for them. Eva then speaks to her father about her last wishes. She tells him she has had a dream about freedom for the slaves, and worries about what would happen to them if her father were not there to protect them. To convince St. Clare that he should free the slaves, she contrasts her carefree life to that of the slaves, which are "pain and sorrow all their lives." Mr. St. Clare tells Eva that he will "do anything you wish," and promises to free all his slaves, especially Tom, when she dies. In a way she is dying for the slaves.

Source(s): http://www.gradesaver.com/uncle-toms-cabin/study-guide/section5/