When I preach from my Nexus 7 (Android), I usually preach from my manuscript in PDF form. Last week, I wrote my sermon in the notes section of logos. In my master note I made each section of my sermon as an individual note.
While preaching, as I finish each section, I swipe to the right and that section deletes and everything moves up. This has been one of the best ways to preach without scrolling and the current section is always at the top. There is an "undelete all" at the bottom and I hit that when I'm done and the entire sermon comes back (of course I preach from a copy of the note just in case the undelete fails)
I'm not sure if the delete function is the same on iPad but if your looking for a way to not get lost scrolling or turning pages, you might want to try preaching from Logos notes and swiping as you progress.
Bill