So I've been thinking about vampires and their aversion to religious objects and, overanalysing as is my wont, I have a few questions:
Are all religious symbols valid or just Christian ones? If the latter, does that conclusively prove the validity of Christianity? If the former, do either vampire or victim have to be aware of the nature of the symbol or would it be sufficient for the symbol to exist even in some distant, unheard of tribe somewhere? Would a cross work for a Jew? Does it depend on the religion of the vampire? If a cross would work, would it be forbidden for the Jew to use one because that would constitute idolatry? Is a Magen David a valid religious symbol, given its relatively modern origins and the lack of religious power attributed to it? Could vampire-shunning be used as a test for the religious validity of a practice or symbol? Can the cross be made out of any material and if so, why don't people just make one with their fingers at the critical moments? If there are limitations on material, what are they? Do they relate to the permanancy of the material, the consistency, or is there a closed list of valid materials? Would a plastic cross do the trick? Would a tattoo of a cross work? Must the vampire see the cross or is general presence sufficient? Can he avoid the problem by closing his eyes? How much of a barrier is required to block the influence of the cross? Is a single layer of material sufficient, and if so, could vampires wear sunglasses, or would protective material be required for all exposed areas of skin? If a priest recited a prayer and spat on the vampire, would that constitute holy water? What if the priest is secretly not a very holy person at all? What if a regular person said a bracha and spat? What bracha would you make? Would it be a bracha l'vatala? If so, would that negate the holiness factor?