Olaf worships Odin. Just like everyone else in eleventh century Sweden. Bob worships Jesus. Just like everyone else in 20th century Alabama.
There is no doubt in your mind that your god, the one taught to you by your parents and worshipped by all your neighbours, is the one and only.
Out of hundreds or thousands of religions throughout time and around the world, only yours is true. Pretty lucky.
God chose one place, in one time, to reveal himself, and let everyone else, around the world and throughout time, worship false idols.
Talk about being in the right place at the right time!
How can this be? How can an actual god choose to reveal himself to a lonely tribe somewhere, sometime, in such an ambiguous way as to leave the world squabbling, if not out right killing each other, over who is right?