The plot, which adapts Lindsay's characters and narrative and features themes drawn from Gnosticism, concerns Thomas Perscors, who is transported from Earth to the planet Lucifer by Seth Valentinus.

He considered it "difficult reading", and different in character from the work of fantasy writers such as C. S. Lewis and J. R. R. Tolkien, in that it avoided "the comforting details of everyday reality".

[3] Bickman wrote that, "Despite the often dazzling imagery and the fast narrative pace, a reader without a detailed knowledge of Gnosticism is likely to be disappointed, if not dismayed", but concluded that the novel belongs, "in large public and academic collections as another facet of one of our most important and controversial literary theorists.

"[4] Leonard compared the novel to the science fiction writer Frank Herbert's Children of Dune (1976) and to Star Wars (1977), and questioned the accuracy of Bloom's treatment of Gnosticism.

[5] Butler compared the novel to Lewis's Perelandra (1943), and suggested that it showed that Bloom was "author of a single complex personal myth", writing that he had used fantasy as "a vehicle for an alternative interpretation of reality".

[9] Bloom stated in a 2015 interview with Daniel D'Addario in Time that after re-reading The Flight to Lucifer, he decided that the novel would "never do", and that, "I had to pay the publisher not to have a second printing of the paperback.