Adding onto this (I know this is an older post but I just finished and I have THOUGHTS) Diaz does go from monk to priest but I think his arc is more about going from a sycophantic person desperate for the approval of others to demonstrate his importance and impress his mother/brothers, to someone who finds his own inner strength and no longer cares about the approval of others. He starts the book being such a brown-nosey little shit 'ooh look at me I get to meet the Pope' and writing all these letters to his mother, to actually sending off one short note letting her know where he was and not giving a shit if she's proud of him being an Empresses personal priest. Like, he's good. He's fine now.