Hello, everyone!
Skimming through RoP: tD, I noticed something peculiar: The "Smite Evil" power of Cherubims ( p21, see Also Michael on p31), which is a kind of DEO on steroids, also affects Faeries ( Magical creatures aren't listed, so one may presume they are unaffected).
This seems pretty strange, especially given the otherwise accepting and relaxed nature of the Divine, so i wonder why it is so. Is it that faeries are less "solid" than magical beings, more ephemeral, and thus more easily disrupted? Or is this because of their link to humanity's belief in them? Could it be that the realm of Faerie has been corrupted by Satan?
It can't be that the Divine is particularly harsh for Faeries, since we know that some of them manage to live, and even thrive, under the Dominion, so it looks like a weird cherubim-specific issue.
I would guess that faeries are evil (or at least harmful) often enough for the Divine to give Cherubim the power to vanquish them alongside demons. Further, I would guess that magic beings as a whole are less disruptive to the lives of the faithful than faeries. Add to that the fact that faeries thrive on stories in a way which often means they are decieving mortals.
Long story short, I don't think this needs to be read as an actual judgement of the Divine on the entire realm of Faerie. But it is an acknowledgement that faeries can and often do work against the Divine Will - see the many faeries who commit or encourage various sins.
I think a key point is that many pagan or "false" gods (not the infernal version) are faeries looking for some vitality, while magic beings tend to be more withdrawn. As such faerie beings wind up competing with the Divine for worshipers and followers, where magic beings do not.
Faeries are effectively living lies that are constantly trying to suck up the attention of humanity. Vanitas vanitatum! This is bad in the Divine's view, as it distracts humanity from what it should really focus on.
It's really bad when such attention-craving actively hurts humanity. For example, a faerie monster terrorizing villagers, or faerie ergot driving people mad.
It's really really bad when such attention-craving not only distracts from good behaviour, but actually encourages sin too. For example, a faerie god demanding worship, or faerie temptress seducing a man away from his wife. Or a brownie encouraging laziness!
But whether it's just bad, really bad, or really really bad, it's fundamentally almost always bad at a primal level, in the way that a lie is fundamentally bad even when its purpose is good. There may be rare exceptions, and I'd expect those to be immune to the Smite Evil power, or the negative effect of Divine Auras (which also affect harshly all faeries, with only a handful of specific exceptions). For example, a faerie that derives vitality from stories of moral redemption - nudging sinners to realize that what they've been doing is wrong, repent, and embark on a journey of penance and reparation - may be on the good side of the Divine. Just maybe.
In addition to "Faerie" in Ars Magica including all the pagan gods & spirits that Christianity is supplanting, there's also a tradition that faeries are the fallen angels who would not choose sides. I'm not sure how far back that goes, but apparently at least into medieval/renaissance timeframes. Either of those would be valid targets for a smiting if they wandered by some place that a Cherub was watching over. While they're not demons, they're demon-adjacent.
Silveroak hit his point right on the head. Magic "gods" generally don't care if they have any worshipers or not. Worshipers do not contribute to their power and in fact can be a major distraction, always bugging them and asking for "favors". Most of them do not care about mortals at all. That apathy means if they do gain worshipers, it is not normally from their actions but rather from people attempting to gain some of their power.
When you contrast that with the Faerie "gods" who actively seek to gain worshipers and build up cults around themselves, it is very clear which would annoy the Divine and which can be safely ignored.
, whereas Magic Jinns remain non-aligned, and Infernal Jinns rejected God.