Another possible answer for what sect of Christian Fiddleford is: A special one only exclusive to the gravity falls universe
The answer that might not be true but that i cling to in my heart: Hirsch cobbled together a couple of popularly discussed traits that different Christians do to make a quintessential "Christian-coded character," without any desire to consult real Christians on whether it'd make sense. Much in the same way goyische media will often cobble together a couple of loose bits of well-known trivia about Judaism to craft what they think a Jewish character would look like
