The Rebellion leadership would even end their briefings with “may the Force be with you.” So it would seem that it’s a belief that has a life outside of the Jedi Order alone.
I’ve always thought of that like people (religious or not) saying “God bless you”, “In God we trust”, swearing in on a bible, ect. Things that have carried over from a more religious age.
Hence the previous sentence that you left off. =P