Sounds like you don’t get around much.
I’m in the Bible Belt; you can barely walk around without someone telling you how Christian they are - whether you ask or not.
When someone tells me unprompted that they’re oh-so-Christian, I ask them to list the Ten Commandments.
Not one of these people has gotten it correct to date, and that includes actual pastors. Also have had the same results with Mormon missionaries, who seem to always come in pairs, and even two of them together can’t do it. Best anyone has done so far is to get seven of them.
Try it. You may be shocked at the results.
I’ve concluded that someone who is really Christian is too humble to shove it in someone else’s face.