Arguments for Markan Priority (that Mark was the first Gospel written)

For reasons related to an unusually convoluted thread (I’d be surprised if anyone can even detect the thread!  I myself barely can – it has to do with Jesus’ view of the afterlife) I need to answer a reader’s question about why scholars think the Gospel of Mark was the first to be written (once I do that, I can show how Luke often changed Mark, which will get me back to Luke’s treatment of Jesus’ rejection in Nazareth, which will get me back to the parable of Lazarus and the rich man, which w...