My father and his siblings said their mother had been disowned by her northeastern Pennsylvania parents because she married a Catholic. My dad always carried his father's small crucifix as a key fob. My grandfather died before I was born. He never went to church and his kids went to Episcopal church in Norfolk, VA and I believe they attended a Baptist church in Baltimore at one time. There are few other hints. My aunts and uncles were less than helpful with tracking my grandfather. My father's older brother told me to just leave it alone and write fiction, it's more interesting. Their younger brother spent a lot of time with their father during WWII but he too had little to report. Most of the stories he told me were a bit twisted once I knew the facts, but that could have been due to his age when he learned them. My younger uncle's name was John, btw.My Dad was George Patrick, named after his uncle George Noble. My elder uncle was Robert James, named for his father.
I haven't double checked my records, but I believe my great grandparents married in 1852, so there would be no direct connection -- your John is very unlikely to be a sibling of my grandfather or my great grandfather. But he could be a cousin. My great grandfather's father was Andrew Noble. He would have been born about 1800, give or take some years.