Edgar Allan Poe's "Masque of the Red Death" is heavily alluded to in the novel's epigraph. In his introduction to Poe's short story, Poe expert, G.R. Thompson, explains that in the Renaissance productions "it was the custom to perform masked balls and plays that symbolized the interpenetration of the realms of Heaven, Earth, and Hell" (source). Seems to us that King is definitely drawing on this idea, though there isn't much discussion of heaven or divinity. Heaven, in the novel, might be represented by the rare moments of peace and optimism the characters find at the hotel, or even by their idealized notions of the hotel as a place where all their dreams can come true. The ideas of hell and earth are pretty obvious. The interplay of the three creates lots of tension and lots of food for thought.
The motif of masks and unmasking is also crucial to the novel. When the truth of the Overlook is revealed to the Torrances, it's a kind of unmasking. The Torrances, themselves, are also unmasked. Ironically, Jack is completely masked by the Overlook, after destroying his face with the roque mallet only to have it taken over by the faces of the hotel's spirits, he thinks that his mask is finally off. Sadly, Jack never takes off the mask he gained in childhood, the mask that says he must follow in his father's footsteps. Danny on the other hand, presents a hopeful version of unmasking. His experience at the Overlook is an unmasking of sorts, a rather brutal unmasking of life, but also an unmasking of the truth of who Danny is. In addition to learning he has great courage as well as human frailty, Danny's identity is validated by Halloran when he acknowledges his ability to shine. Halloran helps Danny see that his abilities are real and that he's not alone.