But it's not.
Ancient bowls have been found that date between the 2nd an 8th centuries AD. They were used to capture evil, the devil, demons, etc. It was believed they had the power to do so.
Interesting that this "need" to be protected arose AFTER the coming of Jesus, historically speaking.
Also interesting, is that the script inside the bowl is just bits and pieces of "real" languages, indicating that were created to pacify the public, at least on some of them.
I firmly believe that we can give power to anything we wish, so if they believed that these bowls protected them, then that faith would be enough unless the faith was tainted with fear, in which case any item or belief would be rendered useless.
Then again, I would believe that they capture negative energies, rather than giving a specific name to the entity, such as devil or demon. How do we know that all of those energies which we consider to be demonic actually consider themselves to be demons? Maybe they're just angry spirits wreaking havoc on all those people that they despised while on earth.
Okay, yes, I jest - a bit. But IF I was to give such power to a "bowl," I would definitely not place limits on which type of negativity it should capture.
I'd say - "Get 'em all!"
I continue to be fascinated learning about ancient religions, practices and the cultures of those who came before us.
The picture below is from Ancient Peoples.
You can learn more about this practice and other bowl discoveries from Biblical Archaeology's Magic Incantation Bowls.