Like Godfrey Higgins a half-century earlier, Massey believed that Western religions had Egyptian roots. Massey wrote,
The human mind has long suffered an eclipse and been darkened and dwarfed in the shadow of ideas the real meaning of which has been lost to moderns. Myths and allegories whose significance was once unfolded in the Mysteries have been adopted in ignorance and reissued as real truths directly and divinely vouchsafed to humanity for the first and only time! The early religions had their myths interpreted. We have ours misinterpreted. And a great deal of what has been imposed on us as God’s own true and sole revelation to us is a mass of inverted myths.
One of the more important aspects of Massey’s writings were his assertions that there were parallels between Jesus and the Egyptian god Horus, primarily contained in the book The Natural Genesis first published in 1883. Massey, for example, argued in the book his belief that: both Horus and Jesus were born of virgins on 25 December, raised men from the dead (Massey speculates that the biblical Lazarus, raised from the dead by Jesus, has a parallel in El-Asar-Us, a title of Osiris), died by crucifixion and were resurrected three days later. These assertions have influenced various later writers such as Alvin Boyd Kuhn, Tom Harpur, Yosef Ben-Jochannan, and Dorothy M. Murdock.