Hollywood films about religious topics are themselves exemplars of the odd confluence of business sense, personal enthusiasms and artistic striving - yeah, that last does poke its nose in, occasionally - that encourage the continual reuse of familiar material. It's a positive virtue, from a commercial POV, that everyone knows these stories and a lot of people already like them - and moreover, have liked them again and again and again.
As someone put it recently, what the studio folks know is that someone has paid to see these things at least once, which is more than they know about something new.
The source material can be folk myth - "Robin Hood" - or religious stories concerning Moses or Christ or Noah's ark, or modern inventions like the Bram Stoker Dracula or Frankenstein, or a popular book or previous movie of the last few decades. What the folk and religious mythology, as well as older popular culture characters, have in common and as an advantage are that they belong to no one; no rights to The Three Musketeers need be secured and no money split with the copyright or trademark holders.
Or, as DeMille famously explained his reasoning for making Biblical films, when asked by an admirer: "Three thousand years of advance publicity."
