I also figured the Collinses to be Congregationalists based upon the history of that particular part of New England. Julia Hoffman was Jewish; Professor T. Eliot Stokes was either an Episcopalian or a Presbyterian because of his rather regal mannerism (you know what Reverend Lovejoy always says about those "snooty Episcopalians" on The Simpsons); the DuPres' were, of course, Catholic. As an aside, and we even discussed it a bit quite a few years ago here, I surmised that, in PT1841, the reason why Josette DuPres Collins, the wife of the late Barnabas Collins, was never fully accepted by the family was because she was a Catholic, and 18th/19th century American Protestants had certain views about "one of them" marrying into their families.
As for me, I believe in being a decent human being. I'm just not practicing right now.
Gerard