When sinful thoughts regarding the beautiful Romani woman Esmeralda enter Frollo's mind, he "panics and seeks to rid himself of [its] source". This internal struggle prompts "Hellfire", which has been described as "one of the best Disney villain songs of all time". Frollo "confronts his lusting for Esmeralda, blaming her for turning towards darkness, and pleading to be saved". He sings "destroy Esmeralda, and let her taste the fires of hell, or else let her be mine and mine alone" while the image of Esmeralda "provocatively danc[es] in front of him".

This "scene of lust and longing" that the song is centered on received much press coverage at the time of the film's release, along with the alterations made to give the film a PG rating.

The song was intended to contrast with the song "Heaven's Light", which was sung by Quasimodo moments earlier, expressing his desire for love and hope that Esmeralda may love him, while "Hellfire" focuses on Frollo's internal conflict between his feelings of lust for her and his conscience and hate for the gypsies.

Both songs, which are sometimes referred to collectively as "Heaven's Light"/"Hellfire" (for example on the soundtrack where it is track 7), describe two opposing views towards the same woman. Quasimodo sees love as "Heaven's Light" and expresses a pure hope for Esmeralda, while Frollo feels only lust for her and therefore views her as a "Hellfire".

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Wikipedia