There are several different end­ings to the Gospel of Mark found in the vari­ous Greek manuscripts. Most Greek texts and several ancient transla­tions conclude with the ending familiar to us as Mark 16:9-20. The ear­liest Greek manuscript with that ending is from the fifth century, but evidence from the church fathers suggests that it was already in existence during the second century. Many scholars feel, however, that the vocabulary and themes of the traditional ending are inconsistent with the rest of the Gospel.

In the two oldest Greek manuscripts and in a number of ancient versions, Mark’s Gospel ends at 16:8. Clement of Alexandria and Origen show no knowl­edge of any ending of this Gospel account beyond verse 8, and Eusebius and Jerome affirm that nearly all Greek manuscripts known to them were con­cluded with this verse. Most scholars believe that this is indeed the point at which the original Gospel probably ended and suggest that the other endings very likely developed dur­ing the second century, after the Gospel of Mark was read alongside the other Gospels and appeared, by comparison, to lack a satis­factory conclusion. Despite its abruptness, Mark 16:8 is arguably an appropriate ending for the Gospel, since one of its motifs is the fear caused by God’s powerful work in and through Jesus (see, e.g., 5:15,33; 9:6). The women’s fear suggests that God had performed one more climactic, powerful work, confirming the testimony of the empty tomb and the angelic announcement that Jesus had indeed arisen from the dead just as he had prom­ised (8:31;9:9,3T; 10:34).

Source: New International Version Archaeological Study Bible