Not sure whether this would fall under more the realm of Rules Question or Advice, but I'll put this here and see how it goes.
Here is the hypothetical situation;
A divine spellcaster in service of Sifkesh, in this case an Infiltrator Inquisitor, has infiltrated a group devoted to Sarenrae. This individual tries to cast a spell that requires a divine focus.
Do they have to present the unholy symbol of Sifkesh, or can they instead present the holy symbol of Sarenrae?
If the latter, is there any way around this problem? Infiltrating an enemy faith, setting up heretical beliefs, corrupting the church, and so on.. is a bit difficult to do when your means of casting spells winds up displaying to anyone of that faith paying any attention that you are not of that faith.
RAW they must present their own holy symbol (of Sifkesh).
If Sifkesh wants his infiltrators to do otherwise, he/she/it (not familiar with Sifkesh) should give them (the archetype) a special ability to cast with other deities' holy symbols in some fashion.
It's probably an oversight that they didn't, so if you're the GM, I recommend houseruling that when you prepare spells each day you can pick one (and only one) specific symbol, the copy you are holding, to act as your holy symbol for the day.
If you're the player, you might get away with inserting a small Sifkesh symbol into the back of a large Sarenrae symbol. Or even having a Sifkesh symbol in one hand (maybe even just on a string around your neck, inside your shirt) and a Sarenrae symbol in the other.
RAW they must present their own holy symbol (of Sifkesh).
If Sifkesh wants his infiltrators to do otherwise, he/she/it (not familiar with Sifkesh) should give them (the archetype) a special ability to cast with other deities' holy symbols in some fashion.
It's probably an oversight that they didn't, so if you're the GM, I recommend houseruling that when you prepare spells each day you can pick one (and only one) specific symbol, the copy you are holding, to act as your holy symbol for the day.
If you're the player, you might get away with inserting a small Sifkesh symbol into the back of a large Sarenrae symbol. Or even having a Sifkesh symbol in one hand (maybe even just on a string around your neck, inside your shirt) and a Sarenrae symbol in the other.
Thank you. Its unfortunate that is the case, that a house rule would be needed to get something working as it likely should..
Sifkesh is the Demon Lord of Heresy. Her whole thing is corrupting people's beliefs, forming groups that draw people away, and then getting people to commit suicide when they realize what they have done. Very big on corruption like a devil, which she is believed to have once been, devours souls like a daemon, but is in fact a demon. Its kind of hard for her followers though, to pass themselves off as members of a different group if their Clerics, Inquisitors, Antipaladins, Warpriests, ect.. have to use a demonic rune when a divine focus is needed. A Knowledge (Religion) check by anyone present kills it, and it wouldn't take that to know it isn't the symbol of one's own faith, just a perception would do that if a roll was even needed.
You could always take the birthmark trait.
Birthmark
You were born with a strange birthmark that looks very similar to the holy symbol of the god you chose to worship later in life.
Benefits: This birthmark can serve you as a divine focus for casting spells, and as a physical manifestation of your faith, and it increases your devotion to your god. You gain a +2 trait bonus on all saving throws against charm and compulsion effects.
When you cast the spell use the birthmark for the divine focus, but have a holy symbol of Sarenrae in your hand as if you were using that.
Or get an unholy tattoo. I'd allow a sleight of hand check or something to fool others.
You can create reliquary armor, shields, or weapons with Create Reliquary Arms and Armor. It doesn't actually say that they have to show the holy symbol, just that they can be used a divine focus. So you can just channel stuff through your weapon. The constant desecrate could be a problem, but you could try to hide it, or turn it to your advantage. As you pass by altars and stuff, it would seem like the deity's connection the church is faltering, as if she's displeased with them. They'll feel like they're doing something wrong, and you could use that to manipulate them. You can start secretly replacing other people's stuff with other reliquary versions, so that if people find out about the weapons, it doesn't look like it's your fault. Start manipulating some people into forming groups, and turn the church against itself. Once it's weakened, swoop in and kill the survivors. Move to another church and repeat.