Sometime in the 50's or 60's I think, I watched a movie about the hunt for a reported lost book of the bible that refuted the current information, thought that it starred David Jannsen but have found no such movie, had female lead but can't remember her name.

It isn't from the Fifties/Sixties.

The Word (1978 TV miniseries)
Starring David Janssen, James Whitmore, Florinda Bolkan
IMDb synopsis:
A document is discovered that appears to be an ancient eyewitness account of the life of Jesus Christ. A public relations executive is hired to publicize this document as a new version of the Bible, but he finds himself enmeshed in controversy and intrigue.


The Word (TV Mini-Series 1978) - IMDb

NOTE: Be warned that the chopped-down version is very little like the original 480-minute miniseries. The edited version is only three hours long.