I also don't generally discuss my religious beliefs unless directly questioned about it -- and since being so-questioned is quite rude, I would likely try to avoid the person questioning me going forward -- thus avoiding any discrimination risk.
My family are all southern fried baptist. I lied to my grandfather who asked me on his deathbed if "I was saved". Otherwise, religion is just not on my mental radar.
Amusingly, the reverse discriminatory problem is sort of true. If someone goes out of their way to tell me about their religious beliefs, I will think less of them. I'm trying to work on this about myself, though.
I think there are bigger problems to solve personally, but this one seems like a cheap "win" so hey, why not I guess?
$0.02