Earlier quoted context omitted.
Many major religions are monotheistic by definition. The entire premise is that only 1 true god exists. Saying we "agree on 519 of 520 and disagree on 1" is a non-statement. The first person's belief in that 1 by definition precludes his belief in the other 519.
I think many people may be missing the point. The point of the argument is to challenge people to question whether the existence of their god is any more plausible than any of the other thousands of deities whose existence has been postulated. It works well against Christians or anyone else whose god has specific and well-defined properties. It doesn't work against deists since their "god" is sufficiently poorly-defi…
Contemporary thinkers might argue that god is well-defined, but ineffable.