The complete title of this novel by Mary Shelley is "Frankenstein, Or the Modern Prometheus". This alternative title for the novel compares Victor to the Greek God, Prometheus. Prometheus had been punished severely after he had given to the people his knowledge of fire. In the novel, Victor ends up suffering as a result of his attempts to give the secret of life. Therefore you could say that fire is symbolic of life in "Frankenstein".
"...and the cottage was quickly enveloped by the flames, which clung to it, and licked it with their forked and destroying tongues." The creature burns