Are there physical characteristics that you pick up on that just makes you know without asking, that person is a believer.
It's fairly easy in my area because it's generally assumed one IS a Christian until proven otherwise, and because it's popular to use "tells" such as cross and religious bumper stickers on vehicles, "faith" jewelry, signs and banners in personal work spaces and public businesses, and, of course, prominent tattoos. Oh, and the frequent use of the expression "Have a blessed day!"
if you replace the word with (muslim) then yes i just know.
There are some that stick out more than others but I try not to judge if possible. But on the average, if you line up 100 people, the odds are in favor of being more xtians than not unfortunately those are the facts.
I don't think i do. The dress code i know of helps me or gives me an idea of their denomination. I don't think i could pick out a Christian in a crowd unless they make certain statements and even thats a maybe. I kind of mind my own business. I do a lot of reading and studying to keep my mind occupied.
I can do that with Mormons. Really easy with Hutterites and Mennonites, too.