My comparison is based on sciencse vs. fiction. 1+1 = 2 is a reality which works in german, africa, usa and everywhere else. There might be a difference on how those symbols (1, 2...) look like but the axiom is true and valid and is discoverable.
In religion its not.
Concept of god exists but it looks different depending on your believe. Multiply gods, one god, good god, bad god...
Even the stuff written down is based on someone who wrote it down and still people interpretate it totally different.
Never seen someone implying they are right that 1+1=3 if the interpretation of 3 is not 'next after one'.