A friend was showing me this book the other day and I can’t remember the name for the life of me. All I remember is that it’s some sort of alternative bible (I think) and it starts with an “O”. I think origin is America late 1800’s.
Ok, doesn’t quite match, but are you talking about the Urantia Book ?
It claims to be from the mystical visions and whatnot from a family in the 1911s onward, but it was first noted in th 1950s, so it may be a little later than what you’re thinking of.
It is very “Bible-like” with chapters, and talks about very biblical-sounding elements and characters.