Wear anything less than your Sunday best to a non-denominational church and fundies will declare that you are a liberal compromiser with itching ears who is giving less than your best to God. On the other hand, if you wear overalls and a straw hat to fundamentalist church on a previously agreed upon Sunday, that’s just being ‘old-fashioned’ which is a whole ‘nother thing entirely.
There is a fundamentalist principle at work here: “It is not ok to do something they way they used to do prior to the 1950’s unless you explicitly state that you are doing it merely to demonstrate or imitate the way they did it prior to the 1950’s.” It is this reasoning that accounts for phenomena such as male college students wearing a button that proclaims that the reason for their lengthy hair style is that they are in a dramatic production set in the 1700’s. It’s the nearest fundy equivalent to special dispensation.
Be sure to stay for “dinner on the grounds.” The fried chicken is mighty fine.
Thanks to @Viniator3 for the idea