Math is a religion to me because it seems impossible to disbelieve it, even though it is an entirely abstract proposition. And furthermore, it seems to produce so much from nothing, and then these productions correspond to our experience, and “organize” them, as we might say.
There are many other ancillary observations ... that it has rituals that resemble prayer, for example ... that it has PRIESTS ...
Oh, I can easily disbelieve the math in my checkbook, best to double, double check checks! ;-)