Usually when you want to add your sermon notes. you want to add sermon notes and tell the system that you’ve just added sermon notes somewhere.
By uploading your notes pdf to the post through the media manager, you’re already doing so, because when you upload your pdf there’s a host of calculations and settings that happens in the background.
Some of the settings will tell wordpress that a pdf was uploaded to that post, and that’s all that WordPRess needs to know.
Thus uploading your Pdf’s with the media manager whlie you are in the sermon post editor for a post is all that’s needed to show the sermon notes in the sermon block.