Flying spaghetti monster and other invalid parallels
The problem with using an article of disbelief as an article of faith is just that.
In the act of assigning the belief condition of non-existence to an article such as FSM, it couldn't then be used again in a capacity which opposes this very belief condition.
Plain English version:
Let's say that I've came up with the Teleporting Giant Unicorn. I would say that it eats FSM for lunch because instead of flying, it teleports super fast and TGU would just gobble FSM up before FSM could fly anywhere.
Unfortunately, I can't convert anyone from the Church of the FSM to the Church of the TGU because
One, I don't even believe in TGU- I just made it up as a parody of FSM and
Two, people in the supposed Church of FSM don't really "believe" in FSM in the same way for pretty much the same reason so it's not like a conversion of faith anyways (unless they've managed to extend intellectual dishonesty and ignorance so far as to claim to not know the parody status of FSM)
As such, you can't compare something like FSM or TGU to something someone actually believes in the full metaphysical existence of.
In the act of assigning the belief condition of non-existence to an article such as FSM, it couldn't then be used again in a capacity which opposes this very belief condition.
Plain English version:
Let's say that I've came up with the Teleporting Giant Unicorn. I would say that it eats FSM for lunch because instead of flying, it teleports super fast and TGU would just gobble FSM up before FSM could fly anywhere.
Unfortunately, I can't convert anyone from the Church of the FSM to the Church of the TGU because
One, I don't even believe in TGU- I just made it up as a parody of FSM and
Two, people in the supposed Church of FSM don't really "believe" in FSM in the same way for pretty much the same reason so it's not like a conversion of faith anyways (unless they've managed to extend intellectual dishonesty and ignorance so far as to claim to not know the parody status of FSM)
As such, you can't compare something like FSM or TGU to something someone actually believes in the full metaphysical existence of.