Given the religious undertones in "The Pit and the Pendulum" – what with the Inquisition and the hellish pit – Poe is pretty much obligated to use some Biblical imagery. And use it he does: in this case, some passages from the Book of Revelation.
The first and most direct allusion comes right at the story's beginning, when the narrator describes the candles sitting on the judges' table. At first, the candles resemble angels sent to save him, but they all too quickly vanish into nothingness. In the Book of Revelation, candles take on an entirely different meaning:
And I turned to see the voice that spake with me. And being turned, I saw seven golden candlesticks;
And in the midst of the seven candlesticks one like unto the Son of man, clothed with a garment down to the foot, and girt about the paps with a golden girdle. (Revelation 1:12-13)
In Revelation, the candles burn brightly around a man who resembles Jesus Christ; in Poe's story, they illuminate all-too-briefly the pale, black-robed judges. The Book of Revelation concerns the Judgment of Man – and is filled with more than its fair share of dark, gloomy imagery – but, here, Poe seems to be perverting that imagery in the name of horror. Awesome or blasphemous? You decide.
At story's end, Revelation returns in the form of blasting trumpets and the "grating of a thousand thunders" (39). In Revelation, seven trumpets accompany the opening of the Seventh Seal; each blast brings with it terrible consequences for humanity. In our narrator's case, however, the trumpets signal his salvation. Once again, Poe kind of turns the biblical imagery on its head. Whatever else, it's definitely creepy.
What other biblical allusions did you notice in Poe's story? Is Poe himself being a heretic by corrupting these images? And if so, why does he have his protagonist pray when he's about to die?