Do you think they can make magic potions?
Do you think they can summon demons and ride on brooms?
I believe everything Fr. James LeBar, the excorcist for the archdiocese of New York, says they can do.
Since I know you won't listen to the shows, I'll give you some highlights. He states that The Exorcist is accurate in its portrayal of possession, except that it shows all cases "rolled into one."
He also repeated a story told to him by a bishop who witnessed a person moving around his hospital room ceiling like a fly.
Regarding your tongue-in-cheek questions:
Do you really think people can do magic spells?
Yes. I think Fr. LeBar addresses that topic. (It's also Biblical)
Do you think they can make magic potions?
Yes. I think Fr. LeBar addresses that topic.
Since you're a materialist reductionist, you may ask, "how can this be possible?" It is possible not because of the ingredients in the potion, but because of the super or extra-natural power of the devil who cooperates with the person casting the spell for his own purposes, giving the appearance of the potion's efficaciousness.
Some Satanic curses, for example, require the sacrifice of infants. It should be obvious why the devil would cooperate with the person casting the spell in this case.
Do you think they can summon demons and ride on brooms?
Summon demons? Certainly. Listen to Fr. LeBar. It's also Biblical. See the account of the witch of Endor.
Flying on brooms? Never heard of it. But occultists can do "astral projection," as Fr. LeBar attests.
I honestly didn't think there were adults who believed in that stuff literally.