Firstly, I think people are not born good or evil but are born blank as a sheet, a white, clear sheet. However, people are only becoming evil that they are affected by others and making evil choices.
Madame Defarge is a nice example in a tale of two cities that is affected to be evil when grown up. I think she was blank as a sheet when she was small, but then she was affected and turned to be cold by the death of her sister and brother. They were dead because of the French aristocracy - Envemode family. After that, she heart turn steel and she chose to the road of hatred and revenge. She wanted to take revenge on the Envemode family and take revolution when she saw how poor peasants in France are. She was not evil at first, she wanted change the life of French peasants, and however, she was evil then that she was too blind about her revenge desire. She wanted to kill the French aristocracy off but not only the Envemode. She had ever said, "To me, women! What! We can kill as well as the men when the place is taken!" She did not realize the way of forgiving. She was just repeating the tragedies even through French peasants were not the victims. People all killed and wars were everywhere. She has chosen the way of taking revenge that brought her to the road of evil. If she has chosen the road of forgiving and goodness, tragedies probably have not been happened.
In the other hand, Sydney Carton is another great example in a tale of two cities that is affected to be good when once he met Lucie. Lucie is his light in his life. Before he met Lucie, he is reckless, he was frustrated and just let people take advantage in him that he thought he has nothing to do so in life. But then when he met Lucie, he became alive, although he was still low self-esteem and frustrated, he said that he