Proof of the guidance of Mohammad and Ali.

[Edwardo Piet]

I will begin to say, given God exists, we would expect his system that he has established such that it guides to the truth, because it doesn't befit a being worthy of worship to misguide as oppose to guide to the truth.  

Alasdair, I think this is the premise that I began with and you disagree with.

Nope. You're backtracking now. This is the premise and what we must assume/take for granted:

What we will be taking for granted: We will take for granted God exists.

You can say now that you meant differently... but what you said was that ^^^this^^^ was what your premise was and what we were taking for granted.