What do those who are anti-religion mean when they say "keep it in your homes and in your churches"?

i think you have possibly misunderstood, obviously i can not speak for others i am not someone who says that, but i think they are quoting christian philosophy. i don't think that they are suggesting that you should not be allowed to where a silver cross or any public display, but that christian philosophy does not permit such acts. i think rather than suggest that you should not be allowed to do these things rather suggesting that you are being hypocritical for doing these things, according to the philosophy you are claiming to follow.