okay idk if anyone's mentioned this yet but i think frank langdon is an irish catholic (prepare for a ramble before i get to my actually point. i'll add a tl;dr)
but aside from the obvious of frank quoting blessings from a priest, taking abt fatherhood, something that is now clearly an issue (or was an issue but is now brought to the forefront due to his addiction) with him no longer wearing tanner's bracelet, and also symbolising his spiritual journey through rehab and recovery (a very common experience due to the spiritual nature of NA and AA).
what stuck out to me, is that he referenced the priest, john o'donohue. john o'donohue was an irish catholic priest that was born in ireland and spoke irish, a lot of his work is steeped in celtic/irish culture. this implies that potentially frank was raised irish catholic.
i had a theory that frank was likely irish, his family being irish immigrants to the us at one point or another. ignoring that langdon is an english surname (i do not assume that his family is solely irish), patrick ball, not only is called patrick a very common irish name to the point its a stereotype, but his middle name is marron, which is irish. not to be too parasocial or anything, but patrick is likely irish/has irish heritage. so i think it makes sense to assume that frank is/does too.
TL;DR. frank was likely raised irish catholic, due to him connecting with irish catholic literature post-rehab as a part of his spiritual recovery
lil irish quote that i think is sweet in the context of frank's recovery:
am agus foighne a thógann seilide go corcaigh
which literally means 'time and patience brings a snail to cork'
