The Robe was a book published in 1942. It quickly rose to #1 on the New York Times bestseller list for nearly a year and stayed on the list for another two years.
The reason it was such a bestseller was the Protestant style preaching in the book. I read the book and this stuff was, shall we say, like listening to a sermon. It is because of this preaching that the book sold so well probably among the Protestants of the Bible Belt. There is no mention of the Catholic Mass, Eucharist, sacraments or any of that.
The movie dropped all the preaching and many scenes associated with it.
In the book, the final last scene with Caligula was nowhere near as interesting as the movie. Caligula just wanted to get rid of Centurion Galleo, and after condemning him Caligula calmly said he thought he had something to do and walked away.
There was none of the hysteical, crazed Caligula that made the movie’s end so amazing.
In the book the slave Demetrius was never imprisoned in Caligula’s palace and Centurion Galleo never rescued him, or did anything else of a heroic nature. The movie added all that. The book, written by Protestant minister Lloyd Cassel Douglas, had as its sole purpose preaching the Bible. The movie, made after Douglas’s death, had a different purpose, obviously: to make money.
In the book Centurion Galleo spent a lot of time with Christians and learned enough to deserve being called a Christian. In the movie, Galleo seemed not to know a thing about Christianity, and you have to wonder why he sacrificed his life, not to mention Diana who didn’t have a clue what this new religion was .