Be careful when examining family Bible records concerning births, marriages, deaths and other events. These entries may not be primary records, but instead are secondary sources and require additional proof of their veracity. They may have been entered or transcribed later, thereby making their accuracy questionable.
Check the copyright or publication date of the Bible. If dates on family entries precede the Bible's date, they are secondary sources. If all the entries appear to be written in the same hand, with the same pen or pencil, and at the same time, be skeptical -- they were probably transcribed.
If entries have dates prior to World War II and appear to have been written with a ballpoint pen, they are definitely transcribed. (Ballpoint pens were not patented until 1938 did not come into general use until late in World War II.)