This was a catchy, misleading title that I could not resist, since my essay is not about math vs. religion as one might expect from the title, but rather about math helping religion. Back in 2016 I was reading Dr. Bart D. Ehrman’s blog that he was writing in preparation for his eventual book, The Triumph of Christianity, in which he was considering Rodney Stark’s purely mathematical analysis of the growth of Christianity in the first three centuries. Neither Rodney Stark nor Bart Ehrman described explicitly the underlying mathematical models of exponential growth that they were using and exactly what was meant by a rate of growth. Given the natural audience for the subject, these omissions were not surprising. So I thought I would clarify the math and also offer some variations on the models, which eventually reflected the actual situation more faithfully. See Math and Religion.