Hi, so I noticed that the magic resistance granted by True Faith can be a burden as well as a boon, especially if it's real high. Is there any way to suppress it like you can with Parma Magica?
Read as written, I get the sense that Parma can only be suppressed because it's not an essential quality of the magus, just a tool. I really hope someone with more experience corrects me.
There is an earlier discussion on this forum about beings switching off their MR based on MIght.
Suppressing the MR granted by True Faith is similar.
What is the general relation of the character with True Faith to Magic? Would she even consider abandoning Divine protection against it?
If she has a "real high" True Faith (see RoP:D p.61f Embodying the Light), she might pray for a Miracle instead (see RoP:D p.60f Miracles, perhaps RoP:D p.87 Invoking a Saint and The Church p.13 The Benefits of Devotion).
Well it was my hope that the magic resistance provided by True Faith would only serve to protect against things the faithful would actually need protection from. It came up in game recently, when the group met their new companion as a stowaway on their boat. He has a Ritual Power from ROP:M that can cure light and medium wounds, but has no penetration, and the characters decided to test whether he was lying or not by having him cure their Jewish faith healer companion.
And thank you for referring me to that other thread, but it reminded me of something: when Parma is suppressed, the maga also loses her Form resistance. Could this point to the possibility that innate resistance can be voluntarily lowered?
This tells us, that Hermetic magi know enough about their Form resistance - which after all comes from their command of a Form - to be able to lower it.
What did the companion with True Faith think about being made a guinea pig?
EDIT: If you wish to read, what a Rabbi might have said about such subjection to sorcery, you can start here:
In particular:
As our examination of the biblical legacy leads us to anticipate, these superficially contradictory attitudes [scilicet: about magic] do not emerge from a distinction the rabbis perceive in the character of what is done or attempted, but, rather, from their analysis of the particular qualities and purposes of the individual who carries out the act.
So letting somebody try out something magical on the companion requires at least, that this individual's moral and religious credentials were thoroughly examined before.
Shorthand for roleplaying: "Is he Jewish?" 
IIRC, one of the later supplements had guidelines to temporarily lower a creature's Might for this express purpose.
Would this also apply to Magical Resistance provided by True Faith? YMMV.
I can see sagas in which a component of faith is trusting god's power and all, not relying on magic... until the time when you have a Crisis of Faith, and must learn to accept outside help, that is 
Well it'd have been strange if he had a problem with it since it was his idea. In short, the stowaway was acting manic and the crew they were sailing with wanted to throw him overboard. Only the healer understood his ramblings and offered to help him prove that he was telling the truth, thus saving his life. (Plus, he wanted to see whether or not his powers were bestowed on him by God).
That sounds like an interesting angle!
I think there are several threads somewhere in addition to the one above. From what I recall there are at least two statements (TMRE p.28 and HoH:MC p.90) showing beings can lower their MR. There is also at least one statement that non-Hermetic magi cannot lowers their defenses like Hermetic magi can (HMRE p.10). I don't think the issue was ever really handled clearly.
As for Hermetic magi, there is nothing stating anything about lowering their MR from Forms alone. It may be that PM, interacting with MR from Forms as it was made to do and being able to be lowered, is what enables lowering of MR from Forms. Or it may be that magi can lower their MR from forms in the same manner so they both get lowered together. Again, I don't think this was ever handled clearly.
I don't like treating divine as just another magic ability. My personal Ars Majica world view is that God and Satan are just ridiculously powerful fairies, however, they are so strong they transmit auras and have a range Zeus, etc, are envious of, so that matters.
In any game I'd run, I'd ask two question. Is the magical effect inimical to the being with true faith? It's resisted. Is it helpful? It's not resisted.
If it's not as mentioned above, how does one drop the protection? Stop truly believing in god?
If one can temporarily drop the protection for a good spell, but some sneaky person threw in a bad spell at the same time, why wouldn't god protect the believer?
I appreciate all the above would no doubt be a house rule.
Yeah, that might indeed be an action of a Rabbi respecting God - and testing him just a little bit.
If he e. g. remembered the story of Jonah and asked God for forgiveness before, I'd let him be healed then - and later wonder about God's purpose with that manic stowaway.
The SG's help in role playing all this might be useful.
This is a spell, not the lab activity, so it is not at all a specific case of that lab activity. It even says this "approximate[s]" rather than is a variant or or a specific case of or similar. Regardless, the key here is that willingness allows you to bypass MR, while unwillingness requires beating MR. So the willing target can let you bypass MR.
It says more than that, and I'm sure you know it does if you can talk about it specifically. It tells us exactly why you don't have to beat its MR:
because the spirit chooses not to resist such a command
It's not because there is something special about containers. It's not that there is something special about freedom. It is explicitly because the spirit "chooses not to resist."
That it is specific - and nothing to generalize to other spells - is quite clear, because the ritual Faerie Chains of the Familiar Slave is derived from Enchanting a Familiar.
The ArM5 enchantment requires consent and most likely active support of the future familiar, hence does not need to overcome its MR. The HoH:MC ritual does not require this - hence needs to overcome MR in case of an unwilling target.
You do note, that the paragraph states, that every spirit bound to a container "chooses" not to resist a command to leave its prison - every spirit. Effectively it has no choice here, the prison is a trap and makes it suffer - so it never resists being freed.
Hence both cases - TMRE p.82 and HoH:MC p.90 - cannot be simply generalized into arguments, that magical beings can turn their MR on and off against any kind of spell at their discretion.
Which means consent -> (bypass MR) and no consent -> (must beat MR), right??? That was the entire point. Do you really disagree this is the case here when you're saying it yourself?
Oh, is that what you're doing??? You're misreading what I wrote and arguing against what I didn't say? Why do you bother doing that? Why reverse my statement to start arguing against me? What did I actually say on this generalization that you've been arguing against? I showed there are specific cases that go in both directions so my conclusion was on the generalization was
I don't think the issue was ever really handled clearly.
I said: "consent and most likely active support". Becoming a familiar is not just "consent", but (ArM5 p.104) friendship, genuine admiration, even love and - of course - trust. "Enchanting a familiar is different from other enchantments." The changes the magus undergoes in that process are not determined by him, but by the troupe - considering also the traits of the familiar.
If you didn't argue for that, I am very content. Please take my apologies for understanding you differently.
So we do not have any arguments so far, "that magical beings can turn their MR on and off against any kind of spell at their discretion". That is, what this thread needs to get out of arguments about MR of magical beings with Might.
Correct. What we have for sure are only the following:
As #4 is also true for Warding, where there is no consent at all, having a couple other specific cases where consent matters doesn't make the case that consent is sufficient. We only know it's a necessary condition in some cases. So we are left with nearly all cases never really being handled clearly.
Because it's a test? Because looking at the big picture, being affected by the bad spell is a necessary evil? Because otherwise God is messing with free will?
True. To suggest one outcome is the correct outcome due to logic with divine never works.
When true faith protects, it's all in god's plan. If the true faith protection can be removed and a bad outcome occurs when the believers drops the true faith protection (if it's determined they can drop their protection), it's all in God's plan.
Just to make myself clear, I'm not flaming or trying to be rude, I'm accepting I went for the wrong angle when discussing divine. The "Can God make a rock so heavy he can't lift it", the answer is yes. It's our weak monkey brains that believes it's a contradiction. Pure Logic and divine don't mix.