What does Mark 9:10 mean?
Peter, James, and John most likely hold to the traditional form of Judaism which teaches that God will raise them from the dead at the end of time. What they're confused about is what kind of resurrection could take place only three days after Jesus dies. Like Jews today, they have a tenuous grasp on the Son of Man in Daniel 7:13–14 but completely misunderstand the Suffering Servant of Isaiah 53. Their experience with kings in Israel's past and Gentile rulers in the near-past and present are far removed from the concepts of service and humility, and do not include the concepts of sacrifice, suffering, death, and resurrection. There is nothing in their worldview that gives context to Jesus' words, and Isaiah 53 isn't yet part of their grasp of the issue.This is a key verse about how to interpret Scripture. There are three basic ways to read the Bible. One is somewhat naturalistic, which completely rejects the supernatural elements as metaphor or fanciful tales. Thomas Jefferson exemplified this when he cut all the accounts of miracles from his Bible. Another is to spiritualize elements that seem farfetched. People often do this with end-times prophecies such as the rapture and the millennial kingdom, saying the reign of Christ is actually in our hearts, not on earth.
What the disciples will grow to realize is despite Jesus' habit of using parables to explain spiritual truths, most of the biblical text is meant to be understood literally. The miracles were real. The end-times prophecies will come to be. And Jesus is speaking plainly when He says He will be raised from the dead.