The most significant Christian themes in the novel are asceticism and sacrifice. The asceticism of the early Christians appealed very strongly to the emergent moral consciousness of the early years of Queen Victoria’s reign (she ascended the throne four years before The Last Days of Pompeii was published), and Nydia’s self-sacrifice in helping unite Glaucus and Ione—although ultimately taken to a sinful extreme—is a model of the Victorian ideal of Christian charity.
Nydia’s blindness is symbolic of the Christian need to rely on faith and to trust in the guidance of God; it is in enabling her to do what she needs to do—and in providing Olinthus with an exemplary confirmation of his faith—that divine will operates in the closing phases of the plot. Although the possibility is voiced en passant that the eruption of Vesuvius might be an expression of God’s wrath, akin to the destruction of Sodom and Gomorrah, the narrative voice is very reluctant to endorse that opinion, and the exemplification of the plot’s resolution offers no support to it.
Bulwer-Lytton’s admittedly tentative idea of God is a thoroughly Christian one, in that he assists people in subtle ways to survive and benefit from disaster rather than wrathfully inflicting it; although Arbaces is punished for his sins, it is his own pride and covetousness that lead him to his destruction rather than any supernatural intervention. Nydia certainly qualifies as a mildly mysterious means of working wonders, but she is, nevertheless, an efficient and entirely appropriate agent of good.