I’m not particularly interested in what ancient texts say, but with what can be observed.
You cannot "observe" religion externally, just it's practices, like the eating pork thing your sibling brought up. The practices are the dead portion of the religion, just ways to apply the principles the religion is meant to teach. Just like laws change as culture changes, applications must too, and anyone who views their own religion as just practices probably hasn't read their own ancient text or didn't understand it. Anyway, I have given you what you need to make an observation. You'll have to be a scientist and do a hands on test if you expect to discover anything.