I think they take the teaching they receive quite literally. If you’ve been to a few fundie churches, it’s quite clear that (1) they often don’t spend a lot of time reading the Bible, and certain parts are referred to much more than others and (2) there’s quite a lot of internal variation between groups, and the things they do believe often have very tenuous support if any in the Bible. Then there are those who really do spend a lot of time reading the Bible and try to take it literally, which is often even worse.
As for the letter, I’ve met a few people who write like that. Some foreigners in China make transparent word replacements in their emails to fool the government, such as using “Daddy” for God. Yeah, I know. One of the most conservative people I know writes like this. She’s an ‘ex lesbian’ and strongly supports Kim Davis.
