Post Author: Bill Pratt
We don’t know. Scholars divide sharply on this issue, although it seems that the majority of New Testament scholars believe that verses 9-20 were not part of the original Gospel written by Mark.
Why? Because the two oldest manuscripts containing Mark’s Gospel (Sinaiticus and Vaticanus) do not contain these verses, church fathers Eusebius and Jerome both said that these verses were missing from Greek manuscripts they knew of, the style and vocabulary of verses 9-20 are decidedly different from the rest of Mark, and it would make sense for later writers to add to the Gospel because verse 8 seems like an abrupt ending.
On the other hand, most manuscripts from the fifth century on contain the verses and second century church fathers Justin Martyr, Tatian, and Irenaeus quoted verse 19, thus supporting its early existence.
One popular compromise view is presented by John D. Grassmick in The Bible Knowledge Commentary:
A view which seems to account for the relevant evidence and to raise the least number of objections is that (a) Mark purposely ended his Gospel with verse 8 and (b) verses 9-20, though written or compiled by an anonymous Christian writer, are historically authentic and are part of the New Testament canon . . . .
In other words, the early church accepted the tradition represented in Mark 16:9-20 even though many understood that Mark did not write it himself.
Again, we do not have enough data to determine the answer with certainty, so dogmatism is unwarranted. Whether or not you believe that verses 9-20 were part of the original Gospel, according to Timothy Paul Jones in Misquoting Truth, should not affect “Christian faith or practice in any significant way” because the concepts found in these verses echo ideas found in other Old and New Testament passages (see Luke 10:19; Isaiah 11:8; Psalm 69:21, 29 for references to protection from snakes and poison).