I don’t believe this is intended as a joke, though it should be.  If I’m not mistaken, longtime readers may remember this fellow as one of the brainless blogospheric apologists for Intellient Design creationism we encountered ages ago.  Age has not, it appears, resulted in a maturation of his intellectual faculties.

(Thanks to Daniel Koffler for the pointer.)

UPDATE:  Philosopher John Turri (Huron University College) notes the relevance of the Trinity, missed by Mr. Carter:

Mr. Carter’s example of 1 + 1 is perhaps not the best one to establish that there is a "particularly Christian view" of mathematics. Better, I think, would have been 1 + 1 + 1. Most think it must be that 1 + 1 + 1 = 3. But certain "distinctly Christian" views have it that sometimes 1 + 1 + 1 = 1.  –