Is this more of an American thing ? Here in the UK l would say that it's mostly the JWs and Mormons who choose to keep separate . That is to do with control over members. Both religions that started in the US .
If they come to my door l will engage with them and explain why l believe what l do . I do tend to point out the false prophecies to try to get them to think about that .
I won't mention the Trinity if they don't.
Jan from Tam