5. Changes to the Gospel of Mark give Christians instructions… But these instructions come from an unknown author.
In the King James Bible, the Gospel of Mark ends with 16:20, “And they went forth, and preached everywhere, the Lord working with them, and confirming the word with signs following. Amen.” Most translations of Mark follow the KJV, with varying verbiage for the verses of chapter 16, which closely follow the Gospel of Luke. They appear to have been added by an unknown author or authors other than the original author of Mark, based on the oldest known manuscripts of the work. The oldest extant copies of Mark end at 16:8, and there are numerous copies which indicate the work ended there. One is the Sinaitic copy, circa 370 CE, another is the Vatican copy, circa 325 CE.
There are many theories regarding the gospel stopping abruptly after 16:8, as well as when the additional verses were added. The additional verses describe the Ascension, and are included in the KJV without subsequent commentary, though many newer translations contain notes pointing out the unknown provenance of the subsequent verses after 16:8. Much of the later verses refer to the criteria for salvation (which differ from elsewhere in the Bible), proselytization, and the Great Commission, the command from Jesus to preach the word to all. The Great Commission is to many fundamentalists their Prime Directive, unaware that it was a later addition to the Gospel and of unknown origin.