Throughout the book, A Tale of Two Cities the theme of sacrifice is used to help the reader realize the cost of life, as well as to develop the plot through the effects of those sacrifices. Through the characters of Sydney Carton, Dr. Manette, and Ms. Pross the theme of sacrifice is developed. The theme of sacrifice brings key aspects of the plot together, and Carton's sacrifice brings the novel to closer in the end.
Sydney Carton paid the highest cost of sacrifice with his life, and in doing so he was very similar to Jesus Christ. Carton laid down his life for a man who had never done anything for him and who in fact had abused his relationship as demonstrated on page 191 when Carton describes himself in Darnay's view as "a dissolute dog who has never done any good, and never will." Similarly Jesus Christ let himself be beaten, abused, and killed for the same people who spit in his face. Other people in both cases thought that Jesus and Carton were not thought to be much more that dogs, while they both sacrificed their lives so these people who treated them like dogs could live. Both Carton's and Jesus' sacrifice was inspired by a deep desperate love for which they were willing to do anything. Carton was willing to die for Lucie because of his desperate, scandalous love for her, just as Jesus showed his love for man when he was willing to give up his life for every man. This level of love makes the sacrifice even more valuable and brings things to closure. Finally, Carton and Jesus both knew that through their sacrifice, others could have life. Carton's death breathed life into Darnay just as Jesus Christ's death breathes life into those who trust in him. The importance of their death is that it brings life. The role of Carton's sacrifice in the plot is that the cost of life is sometimes high. Through his sacrifice the cost and privilege of living can be measured, just as Christians can see the true cost and privilege of life through Jesus Christ's sacrifice.
Dr. Manette also sacrificed much of his life by giving up his own personal goals and agenda for Lucie. On page 125 Dr. Manette says, "any fancies, any reasons, and apprehensions, anything whatsoever, new or old against the man she really loved…they shall all be obliterated for her sake." Dr. Manette was willing to relinquish his own personal feelings or perhaps "rights" so that Lucie may be happy. He set aside, "anything whatsoever" in order for Lucie to marry the man she loves. Dr. Manette did anything he could to save Darnay from death, even to the point where Madame Defarge mocked him saying, "Save him now, my Doctor save him!" Dr. Manette had always been suspicious about Darnay, but he put aside his doubts in to Make Lucie happy. Deep down he knew that Darnay was an Evermondé, but he sacrificed his own feelings for Lucie's feelings. Thirdly, Dr. Manette gave up all of his desires, hopes, thoughts of revenge for Lucie, as demonstrated when he says, "She is everything to me; more to me than suffering, more to me than wrong, more to me…." Dr. Manette had years of anger and revenge stored up him from when he was imprisoned, yet he forgot about all of it and only tried to make Lucie happy and make up for the many years he had lost. Dr. Manette's pain was so great.