Last I say on this because I don't want to cross over into something that breaks the board rules.
You are providing one example. Sure, there are religious people that refuse to wear a mask. But, there are people of all beliefs, race, age, sex, etc. that refuse as well.
Many teens and college age adults ignore the mask rules. My daughter got quarantined from school earlier this year because she sat next to a kid in class that was positive. This is high school. The kid would not wear her mask in the classroom because it's only required in common areas and not the classroom. I've seen high school sports fans that take their masks off the second they get through the gate even though the rule is you are supposed to keep it on the entire game, I saw a guy in the grocery the other night with his wife and kid. The guy was not wearing a mask and neither was the kid (who I would put at 7 or 8). Heck, I've got a 90 year old uncle who only ends up in a church for funerals who won't wear a mask.
Yes, the BBQ owner may be religious. But, it's unfair to paint a large brush against religion in regards to mask wearing.