To understand the symbolism behind Frankenstein, you need to take a close look at the title of the novel. The entire title is "Frankenstein or a Modern Promethesus". The author, Mary Shelley obviously wants her audience to make a connection between Victor and the Greek Titan Promethesus, who, according to Greek myth, brought fire to mankind. He was punished for his crime by Zeus who chained him to a rock and had a bird eat his liver each day. At night, the liver would regenerate and the process began again.
Victor's monster, like Promethesus' fire, brought both good and evil to mankind. The monster was a great accomplishment for science, but Victor's inability to care for his creation launched the monster on a road to destruction. Like fire that is untended, the monster grew into a very destructive force.
In addition, Victor was punished severely by the results of his actions. Metaphorically, he had his liver eaten away by guilt, just as Promethesus endured his actual liver being eaten away. Fortunately, Promethesus was finally freed from his trials by Hercules but Victor rejects any help from Robert Walton or his monster and dies never fully understanding that his search for "science" was unnecessary.