One of the reviews says that her service to the poor was more about converting them to Christianity than physical help (paraphrasing).
If you think you can stand justified before God on Judgment day, understand that no one is without sin, and thus we all deserve condemnation. Every religion out there has a bunch of rules to follow (including atheists who don't think of themselves as having a religion) but none have the answer for the inevitable question: what happens when we fail to follow the rules? Even Islam teaches they don't know if Mohammed is in paradise due to this problem. Only through Christ's sacrifice to cover our sins is there a solution to our fallen state.