>To give an example of how much they rely on scripture, they will tell me Mary had 6 other kids after Jesus and she didn't die a virgin
Been going to lutheran churches my whole life and I've never once heard this taught as definitive doctrine.  *at most* one pastor said, "yeah, we're not 100% sure because scripture isn't completely clear one way or the other, so that probably means we don't need to worry about it that much".  Sorry you found some unhinged baptist or something snd that's colored your entire understanding of protestantism though.