Yes, you can smell the fear as the demons sweat, and tremble.
It's not any old "religious symbol" that makes them freak out, it's the cross of Christ. And they are right to fear Him.
Though the cross is perhaps what upsets them the most, other Christian religious symbols also have some effect, like The Holy Bible, and even Holy Water. Which leads to a funny anecdote you might enjoy.
A long time ago I paid a visit to a very old Catholic church on an Indian reservation, still used as a Catholic elementary school and church, and they also have a nice gift shop for tourists, of which they get many. And one of the items there were empty small plastic bottles labeled Holy Water. They had a stainless steel tank with Holy Water in it that could be used to fill the bottles, but I left mine empty.
Weeks later, I was making some habanero pepper picante, and had about an extra half cup of habanero juice. Not having a small, well sealed bottle on hand, I put it in the Holy Water bottle, with the idea of providing some of my hot pepper aficionado friends a sample of what my extremely hot picante would taste like, when I met them later at a coffee shop.
That evening, at the coffee shop, I saw a group of unhappy, Gothic dressed children, all wearing black of course. Their leader, an older boy, professed to be a Satanist and wannabee vampire. He was a rotter, and he was leading the others astray. I didn’t care for him at all.
In any event, we got to talking, and the older boy’s bragging and pretense of menace finally annoyed me enough to ask if he was repelled by symbols of Christianity.
This set him off, saying he was such powerful “eevil” that he was impervious to such things. So I pulled out the bottle of “Holy Water”, showing the label to him and his little friends. So, it wouldn’t hurt you if I sprinkled this on you? Of course not!, he proclaimed.
So I gave him some good splashes, trying to avoid his eyes, being a nice guy.
He immediately went into a Jekyll and Hyde routine, as if the Holy Water was burning him. Then he stopped and regained his composure, and said, see, it has no power over me!
And then the habanero juice kicked in.
After a far more realistic performance of great pain and confusion, he ran off screaming into the night, while his surprised little friends started reevaluating their relationship with him.