Halloween is apparently the fusion of the old Celtic belief of the veil between the worlds getting thin and the dead popping in for a visit, and the celebration of All Hallows’ and the month of rememberence I just read about it. The dressing up is to confuse the devil or spirits so they don’t recognise you. Anyway it’s basically Irish/Celtic so has been around over a thousand years so long established before Presbyterians were.
Looks like Baptist’s can do their own thing depending on which congregation you attend, some are liberal and LGBTQ+ some are conservative